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The relationship between cortisol concentrations in pregnancy and systemic vascular resistance in childhood

RONDÓ, Patrícia Helen de Carvalho; LEMOS, Jesuana Oliveira; PEREIRA, Joilane Alves; SOUZA, José Maria Pacheco de
Fonte: Amsterdam Publicador: Amsterdam
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.07%
Objective. To assess the relationship between cortisol concentrations in the last trimester of pregnancy and systemic vascular resistance — SVR in childhood. Materials and methods. This study is part of a cohort involving 130 Brazilian pregnant women and their children, ages 5 to 7 years. Maternal cortisol was determined in saliva by an enzyme immunoassay utilizing the mean concentration of 9 samples of saliva (3 in each different day), collected at the same time, early in the morning. SVR was assessed by the HDI/PulseWave CR-2000 Cardiovascular Profiling System®. Socioeconomic and demographic characteristics and life style factors were determined by a questionnaire. The nutritional status of the women and children was assessed by the body mass index — BMI. The association between maternal cortisol and SVR in childhood was calculated by multivariate linear regression analysis. Results.There were statistically significant associations between maternal cortisol and SVR (p = 0.043) and BMI-z score of the children (p = 0.027), controlling for maternal BMI, birth weight, age, and gender of the children. Conclusion. As far as we know this is the first study in the literature assessing the association between cortisol concentrations in pregnancy and SVR in childhood. Overall...

Effects of sinoaortic Denervation on Hemodynamic parameters during natural sleep in rats

SILVEIRA, Neide P.; MOREIRA, Edson D.; DRAGER, Luciano F.; SILVA, Gustavo J. J.; KRIEGER, Eduardo M.
Fonte: AMER ACAD SLEEP MEDICINE Publicador: AMER ACAD SLEEP MEDICINE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.19%
Study Objectives: To analyze the role of arterial baroreflex on hemodynamic changes during synchronized and desynchronized sleep phases of natural sleep in rats. Design: Experimental study. Setting: Laboratory. Participants: Seventeen male Wistar rats. Interventions: No intervention (control, n = 8) or sinoaortic denervation (SAD, n = 9). Measurements and Results: Sleep phases were monitored by electrocorticogram, and blood pressure was measured directly by a catheter in the carotid artery. Cardiac output, as well as total and regional vascular resistances, were determined by measuring the subdiaphragmatic aorta and iliac artery flows with Doppler flow probes, respectively. In contrast to the control group, the SAD group had a strong reduction in blood pressure (-19.9% +/- 2.6% vs -0.7% +/- 2.1%) during desynchronized sleep, and cardiac output showed an exacerbated reduction (-10.4% +/- 3.5% vs 1.1% +/- 1.7%). In SAD rats, total vascular resistance decreased during desynchronized sleep (-10.1% +/- 3.5% vs -1.0% +/- 1.7%), and the increase in regional vascular resistance observed in the control group was abolished (27.5% +/- 8.3% vs -0.8% +/- 9.4%). Conclusions: SAD caused profound changes in blood pressure, cardiac output, and total vascular resistance...

Activation of central α(2)-adrenoceptors mediates salivary gland vasoconstriction

Moreira, Thiago dos Santos; Takakura, Ana Carolina Thomaz; Menani, José V.; Colombari, Eduardo
Fonte: Pergamon Press; Oxford Publicador: Pergamon Press; Oxford
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.22%
OBJECTIVE: Peripheral treatment with the cholinergic agonist pilocarpine increases salivary gland blood flow and induces intense salivation that is reduced by the central injection of moxonidine (α(2)-adrenoceptors/imidazoline agonist). In the present study, we investigated the effects of the intracerebroventricular (i.c.v.) injection of pilocarpine alone or combined with moxonidine also injected i.c.v. On submandibular/sublingual gland (SSG) vascular resistance. In addition, the effects of these treatments on arterial pressure, heart rate and on mesenteric and hindlimb vascular resistance were also tested. DESIGN: Male Holtzman rats with stainless steel cannula implanted into lateral ventricle and anaesthetized with urethane+α-chloralose were used. RESULTS: Pilocarpine (500nmol/1μl) injected i.c.v. Reduced SSG vascular resistance and increased arterial pressure, heart rate and mesenteric vascular resistance. Contrary to pilocarpine alone, the combination of moxonidine (20nmol/1μl) and pilocarpine injected i.c.v. Increased SSG vascular resistance, an effect abolished by the pre-treatment with the α(2)-adrenoceptor antagonist yohimbine (320nmol/2μl). The increase in arterial pressure, heart rate and mesenteric resistance was not modified by the combination of moxonidine and pilocarpine i.c.v. CONCLUSION: These results suggest that the activation of central α(2)-adrenoceptors may oppose to the effects of central cholinergic receptor activation in the SSG vascular resistance.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Pesquisa (CNPq/PRONEX)

O ecocardiograma como preditor de variáveis hemodinâmicas nas cardiopatias congênitas com hipertensão pulmonar e nos candidatos a transplante cardíaco; Echocardiographyc estimates of hemodynamic parameters in pulmonary hypertension associated with congenital cardiac shunts or cardiomyopathy

Ribeiro, Zilma Verçosa de Sá
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/03/2009 PT
Relevância na Pesquisa
46.26%
A condição de hipertensão pulmonar é definida como a presença de pressão arterial pulmonar média acima de 25 mmHg em repouso. Esta é a resultante hemodinâmica de vários processos nosológicos que acometem a circulação nos pulmões, notadamente os pequenos vasos pré e intraacinares. A microcirculação pulmonar pode se alterar na presença de enfermidades cardíacas, pulmonares, tromboembólicas, infecto-parasitárias e do tecido conectivo, entre outras. Na ausência dessas condições, o diagnóstico de hipertensão arterial pulmonar idiopática se impõe. Com respeito especificamente à doença cardíaca levando a alterações vasculares pulmonares, temos as situações que acarretam aumento de fluxo sangüíneo pulmonar (cardiopatias congênitas que cursam com defeitos de septação das câmaras ou dos grandes vasos) ou dificuldade de drenagem venosa (disfunção sistólica ou diastólica do ventrículo esquerdo, valvopatia mitral e doenças do átrio esquerdo ou veias pulmonares). As alterações vasculares pulmonares que ocorrem nessas circunstâncias podem dificultar ou impedir o reparo cirúrgico de um defeito congênito de septação cardíaca, ou o encaminhamento de pacientes com doença miocárdica para o transplante. Por essas razões...

Central moxonidine on salivary gland blood flow and cardiovascular responses to pilocarpine

Moreira, T. S.; Takakura, ACT; Colombari, E.; De Luca, L. A.; Renzi, A.; Menani, Jose Vanderlei
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 155-163
ENG
Relevância na Pesquisa
46.28%
Peripheral treatment with the cholinergic agonist pilocarpine induces intense salivation that is inhibited by central injections of the alpha(2)-adrenergic/imidazoline receptor agonist moxonidine. Salivary gland blood flow controlled by sympathetic and parasympathetic systems may affect salivation. We investigated the changes in mean arterial pressure (MAP) and in the vascular resistance in the submandibular/sublingual gland (SSG) artery, superior mesenteric (SM) artery and low abdominal aorta (hindlimb) in rats treated with intraperitoneal (i.p.) pilocarpine alone or combined with intracerebroventricular (i.c.v.) moxonidine. Male Holtzman rats with stainless steel cannula. implanted into lateral ventricle (LV) and anesthetized with urethane were used. Pilocarpine (4 mumol/kg of body weight) i.p. reduced SSG vascular resistance (-50 +/- 13% vs. vehicle: 5 +/- 3%). Pilocarpine i.p. also increased mesenteric vascular resistance (15 +/- 5% vs. vehicle: 2 +/- 3%) and MAP (16 +/- 3 mmHg, vs. vehicle: 2 +/- 3 mmHg). Moxonidine (20 nmol) i.c.v. increased SSG vascular resistance (88 +/- 12% vs. vehicle: 7 +/- 4%). When injected 15 min following i.c.v. moxonidine, pilocarpine i.p. produced no change on SSG vascular resistance. Pilocarpine-induced pressor responses and increase in mesenteric vascular resistance were not modified by i.c.v. moxonidine. The treatments produced no change in heart rate (HR) and hindlimb vascular resistance. The results show that (1) i.p. pilocarpine increases mesenteric vascular resistance and MAP and reduces salivary gland vascular resistance and (2) central moxonidine increases salivary gland vascular resistance and impairs pilocarpine-induced salivary gland vasodilatation. Therefore...

CHANGES IN VASCULAR-RESISTANCE DURING CAROTID OCCLUSION IN NORMAL AND BARORECEPTOR-DENERVATED RATS

Machado, B. H.; Bonagamba, LGH; Castania, J. A.; Menani, Jose Vanderlei
Fonte: Amer Heart Assoc Publicador: Amer Heart Assoc
Tipo: Artigo de Revista Científica Formato: 149-153
ENG
Relevância na Pesquisa
66.25%
In the present study, we investigated changes in mesenteric, renal, and hindquarter vascular resistance during the pressor response produced by bilateral carotid occlusion (BCO) in conscious, freely moving normal and denervated (aortic, carotid, or both) rats. BCO was performed using special previously implanted cuffs. In control normal rats, the increase in mean arterial pressure (MAP) during early and late responses (37 +/- 4 and 21 +/- 2 mm Hg, respectively) was related to increased renal (125 +/- 12% and 45 +/- 10%) and mesenteric (38 +/- 13% and 41 +/- 5%) but not hindquarter (14 +/- 4% and 8 +/- 7%) vascular resistance. In aortic-denervated rats, the greater MAP increase in early and late responses (57 +/- 4 and 44 +/- 4 mm Hg, respectively) compared with normal rats was related to a marked increase in hindquarter (137 +/- 26% and 106 +/- 26%) and mesenteric (104 +/- 14% and 66 +/- 9%) vascular resistance. In carotid-denervated rats, MAP increase and change in vascular resistance were similar to those values observed in control rats. Sinoaortic-denervated rats showed a greater MAP increase (34 +/- 4 mm Hg) during late response and a reduced increase in renal vascular resistance (46 +/- 6%) during early response. The present results show that 1) the pressor response to BCO in normal rats is associated with an increase in renal and mesenteric vascular resistance...

Activation of central aα-adrenoceptors mediates salivary gland vasoconstriction

Moreira, Thiago S.; Takakura, Ana C.; Menani, Jose Vanderlei; Colombari, Eduardo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 167-173
ENG
Relevância na Pesquisa
46.21%
Objective: Peripheral treatment with the cholinergic agonist pilocarpine increases salivary gland blood flow and induces intense salivation that is reduced by the central injection of moxonidine (aα-adrenoceptors/ imidazoline agonist). In the present study, we investigated the effects of the intracerebroventricular (i.c.v.) injection of pilocarpine alone or combined with moxonidine also injected i.c.v. On submandibular/sublingual gland (SSG) vascular resistance. In addition, the effects of these treatments on arterial pressure, heart rate and on mesenteric and hindlimb vascular resistance were also tested. Design: Male Holtzman rats with stainless steel cannula implanted into lateral ventricle and anaesthetized with urethane + α-chloralose were used. Results: Pilocarpine (500 nmol/1 μl) injected i.c.v. Reduced SSG vascular resistance and increased arterial pressure, heart rate and mesenteric vascular resistance. Contrary to pilocarpine alone, the combination of moxonidine (20 nmol/1 μl) and pilocarpine injected i.c.v. Increased SSG vascular resistance, an effect abolished by the pre-treatment with the α2-adrenoceptor antagonist yohimbine (320 nmol/2 μl). The increase in arterial pressure, heart rate and mesenteric resistance was not modified by the combination of moxonidine and pilocarpine i.c.v. Conclusion: These results suggest that the activation of central α2- adrenoceptors may oppose to the effects of central cholinergic receptor activation in the SSG vascular resistance. © 2012 Elsevier Ltd. All rights reserved.

Responsiveness of raised pulmonary vascular resistance to oxygen assessed by pulsed Doppler echocardiography.

Vogel, M; Weil, J; Stern, H; Bühlmeyer, K
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1991 EN
Relevância na Pesquisa
46.21%
OBJECTIVE--To assess whether changes in Doppler echocardiographic indices in the pulmonary artery correlated with changes in pulmonary vascular resistance. DESIGN--Acceleration time, ejection time, maximal flow velocity, and velocity time integrals were measured at the same time as pressure and oxygen saturation measurements in room air and during 10 minutes of oxygen breathing in the catheterisation laboratory. Pulmonary vascular resistance and pulmonary blood flow (Qp) were calculated from catheterisation data by use of the Fick principle. PATIENTS--14 consecutive patients with a congenital heart defect and a left to right shunt associated with raised pulmonary artery pressure who underwent routine diagnostic cardiac catheterisation to assess their pulmonary vascular resistance. RESULTS--Though pulmonary vascular resistance and systolic pulmonary artery pressure fell significantly during oxygen administration, there was no significant change in the acceleration time or ejection time. Peak velocity increased significantly during oxygen administration. During oxygen breathing Doppler derived measurements of pulmonary flow showed a significant increase in Qp similar to the increase in Qp measured by the Fick principle. There was no significant correlation between the fall in pulmonary vascular resistance and the increase in acceleration time or ejection time...

Effects of aortic pressure and vasoactive agents on the vascular resistance of the vasa vasorum in canine isolated thoracic aorta.

Ohhira, A; Ohhashi, T
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //1992 EN
Relevância na Pesquisa
46.2%
1. We have developed a new preparation for continuously measuring changes in vascular resistance of the vasa vasorum of the canine isolated thoracic aorta perfused at a constant flow rate with Krebs-bicarbonate solution. 2. An increase of more than 150 mmHg in aortic pressure caused a significant increase in the vascular resistance of the vasa vasorum. 3. 5-Hydroxytryptamine (5-HT), noradrenaline (NA), adrenaline and dopamine caused dose-dependent increases in the vascular resistance of the vasa vasorum. The decreasing order of potency in the vasoconstrictor responses was as follows: 5-HT >> NA = adrenaline >> dopamine. The 5-HT- and adrenaline-induced vasoconstrictor responses were inhibited by methysergide and by phentolamine plus propranolol, respectively. 4. Acetylcholine (ACh), isoprenaline (ISP), histamine (His), ATP, ADP and adenosine produced dose-related decreases in the vascular resistance of aortic vasa vasorum perfused with the Krebs solution containing 10(-5) M-NA. The decreasing order of potency in the response was as follows: ACh = ISP > His >> adenosine = ATP = ADP. The ACh-, ISP- and His-induced vasodilator responses were antagonized by atropine, propranolol and famotidine, respectively. 5. The results suggest that the preparation described is useful for studying the regulation of vascular resistance of aortic vasa vasorum and that aortic pressure and vasoactive compounds may directly regulate the vascular resistance of the vasa vasorum in canine isolated thoracic aorta.

Lung reflexes and nasal vascular resistance in the anaesthetized dog.

Lung, M A; Widdicombe, J G
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1987 EN
Relevância na Pesquisa
46.18%
1. In pentobarbitone-anaesthetized dogs the nasal vasculature was perfused on both sides, and nasal vascular and airflow resistances were measured together with blood pressure, heart rate and tidal airflow. 2. Capsaicin was injected intravenously to stimulate lung C-fibre receptors, and veratrine to stimulate pulmonary stretch receptors and cardiac receptors. Injections with both drugs were repeated after pulmonary denervation and after cervical vagosympathectomy. 3. Intravenous capsaicin caused hypotension, bradycardia and rapid shallow breathing, together with a decrease in nasal vascular resistance and little change in nasal airways resistance. Denervation showed that these effects came from lung reflexes, presumably from C-fibre receptors. 4. Intravenous veratrine caused similar effects to capsaicin before denervations, presumably due to stimulation of slowly adapting pulmonary stretch receptors. Left atrial injections of veratrine caused hypotension, bradycardia and hyperpnoea, together with an increase in nasal vascular resistance and little change in nasal airways resistance. Thus cardiac receptors seem to increase nasal vascular resistance. 5. Injections of capsaicin and veratrine into the nasal circulation decreased nasal vascular resistance...

The effect of pregnancy on the changes in hind-limb vascular resistance following haemorrhage in the rabbit.

Humphreys, P W; Joels, N
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1986 EN
Relevância na Pesquisa
46.19%
The change in vascular resistance of the skinned hind limb perfused at constant flow has been measured following rapid removal of 10% of the blood volume in anaesthetized pregnant rabbits (27-29 days gestation) and compared with that of non-pregnant rabbits. 5 s after haemorrhage was completed vascular resistance had risen in all rabbits, but in the pregnant ones this increase was only one-fifth of that in the non-pregnant ones. After section of either the carotid sinus and aortic nerves or the sympathetic innervation to the hind limb the increases of vascular resistance at this time were abolished. It is concluded that the previously described diminution during pregnancy of the protective function of the baroreflexes during haemorrhage results, to some extent, from their diminished role in a vascular bed not associated with the reproductive process. The blood withdrawn was not re-infused for 10 min, throughout which, in all rabbits with sinus, aortic and sympathetic nerves intact, the increase in vascular resistance was sustained. After section of the carotid sinus and aortic nerves and the sympathetic innervation there was, during this 10 min, a slow increase in vascular resistance comparable in final size to that which occurred immediately in the respective innervated preparations...

Carotid baroreceptor reflex regulation of forearm vascular resistance in man.

Ebert, T J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1983 EN
Relevância na Pesquisa
46.2%
The carotid baroreflex regulation of forearm vascular resistance in man is uncertain. Forearm vascular resistance, blood pressure and R-R interval responses to carotid sinus stimulation were therefore measured in seven healthy men. Carotid stimuli were delivered by gradually applying neck pressure, neck suction or neck suction during simultaneous low-level lower-body negative pressure. Mean arterial blood pressure and R-R interval responses to neck suction and pressure were immediate and were sustained throughout the periods of stimulation. In contrast, forearm vascular responses, were transient. During simultaneous mild lower-body negative pressure (which decreases cardiopulmonary baroreceptor stimulation and increases forearm vascular resistance), neck-suction-induced forearm vasodilation was exaggerated and sustained throughout the entire period of neck suction. There was a linear relationship between the level of resting forearm vascular resistance and the change in resistance produced by carotid stimuli. It is concluded that reflex changes in forearm vascular resistance provoked by carotid baroreceptor stimuli are immediate and evanescent in man. Simultaneous reduction of cardiopulmonary baroreceptor activity heightens the magnitude and duration of forearm vasodilation induced by carotid baroreceptor stimulation.

Correlations of lung morphology, pulmonary vascular resistance, and outcome in children with congenital heart disease.

Bush, A; Busst, C M; Haworth, S G; Hislop, A A; Knight, W B; Corrin, B; Shinebourne, E A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1988 EN
Relevância na Pesquisa
46.17%
Pulmonary vascular resistance was measured in air, oxygen, and after administration of vasodilators in 14 children with pulmonary hypertension and congenital heart disease. Lung morphology was examined by light microscopy and assessed quantitatively. In this selected group of patients (a) medial muscle thickness of greater than 20% in the intra-acinar arteries and Heath-Edwards changes of I or II were significantly associated with perioperative death from pulmonary complications after cardiac surgery; (b) children with lower percentage medial muscle thickness had a higher baseline resistance (r = -0.84) associated with Heath-Edwards grade III or higher changes (most of these patients were not offered corrective surgery); (c) when the lowest pulmonary vascular resistance was less than 3 units, Heath-Edwards grading was I or II (n = 4). When the pulmonary vascular resistance was greater than 6 units, however, there was no direct correlation with Heath-Edwards grading (n = 9). Four patients with a resistance of greater than 6 units had only grade I or II changes. Three had a medial muscle thickness above 20%, and were among those who died at or soon after operation. It is concluded that (a) patients with a lowest pulmonary vascular resistance of greater than 6 units have a bad prognosis whatever their lung morphology; and (b) some patients with Heath-Edwards grade I or II will have a high resistance (this group has a high medial muscle mass and a poor prognosis and would not be detected by Heath-Edwards grading alone).

Regulation of baseline vascular resistance in the canine diaphragm by nitric oxide.

Ward, M. E.; Hussain, S. N.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1994 EN
Relevância na Pesquisa
46.23%
1. The role played by nitric oxide (NO) in the regulation of blood flow to the canine isolated hemidiaphragm was evaluated by determining (a) the effects of the L-arginine analogues NG-nitro-L-arginine methyl ester (L-NAME), NG-nitro-L-arginine (L-NOARG), and argininosuccinic acid (ArgSA) on baseline vascular resistance and of the latter two agents on endothelium-dependent (acetylcholine, ACh) and endothelium independent (sodium nitroprusside, SNP) vasodilatation; (b) the effects of L- and D-arginine on baseline vascular resistance; and (c) the effects of L-glutamine, an inhibitor of intracellular recycling of L-citrulline to L-arginine, on baseline resistance and on the response to ACh and SNP. 2. L-NAME, L-NOARG and ArgSA (6 x 10(-4) M final concentration) increased baseline diaphragmatic vascular resistance to a similar extent (28.6 +/- 4.2%, 26.7 +/- 4.3% and 32.8 +/- 4.6% respectively). L-NOARG and ArgSA reversed the vasodilator effect of ACh but not of SNP. 3. L- and D-arginine had no effect on vascular resistance. 4. L-Glutamine (10(-3) M) increased baseline vascular resistance by 10 +/- 1.9% (P < 0.05) but did not alter responses to either ACh or SNP. 5. Basal NO release plays a role in the regulation of baseline diaphragmatic vascular resistance. L-Arginine analogues tested potently and specifically inhibited this process. Moreover...

Nanomolar ouabain increases NCX1 expression and enhances Ca2+ signaling in human arterial myocytes: a mechanism that links salt to increased vascular resistance?

Linde, Cristina I.; Antos, Laura K.; Golovina, Vera A.; Blaustein, Mordecai P.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
55.94%
The mechanisms by which NaCl raises blood pressure (BP) in hypertension are unresolved, but much evidence indicates that endogenous ouabain is involved. In rodents, arterial smooth muscle cell (ASMC) Na+ pumps with an α2-catalytic subunit (ouabain EC50 ≤1.0 nM) are crucial for some hypertension models, even though ≈80% of ASMC Na+ pumps have an α1-subunit (ouabain EC50 ≈ 5 μM). Human α1-Na+ pumps, however, have high ouabain affinity (EC50 ≈ 10–20 nM). We used immunoblotting, immunocytochemistry, and Ca2+ imaging (fura-2) to examine the expression, distribution, and function of Na+ pump α-subunit isoforms in human arteries and primary cultured human ASMCs (hASMCs). hASMCs express α1- and α2-Na+ pumps. Further, α2-, but not α1-, pumps are confined to plasma membrane microdomains adjacent to sarcoplasmic reticulum (SR), where they colocalize with Na/Ca exchanger-1 (NCX1) and C-type transient receptor potential-6 (receptor-operated channels, ROCs). Prolonged inhibition (72 h) with 100 nM ouabain (blocks nearly all α1- and α2-pumps) was toxic to most cultured hASMCs. Treatment with 10 nM ouabain (72 h), however, increased NCX1 and sarco(endo)plasmic reticulum Ca2+-ATPase expression and augmented ATP (10 μM)-induced SR Ca2+ release in 0 Ca2+...

Human immunodeficiency virus-1 transgene expression increases pulmonary vascular resistance and exacerbates hypoxia-induced pulmonary hypertension development

Porter, Kristi M.; Walp, Erik R.; Elms, Shawn C.; Raynor, Robert; Mitchell, Patrick O.; Guidot, David M.; Sutliff, Roy L.
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
46.18%
Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary arterial resistance and vessel remodeling. Patients living with human immunodeficiency virus-1 (HIV-1) have an increased susceptibility to develop severe pulmonary hypertension (PH) irrespective of their CD4+ lymphocyte counts. While the underlying cause of HIV-PAH remains unknown, the interaction of HIV-1 proteins with the vascular endothelium may play a critical role in HIV-PAH development. Hypoxia promotes PH in experimental models and in humans, but the impact of HIV-1 proteins on hypoxia-induced pulmonary vascular dysfunction and PAH has not been examined. Therefore, we hypothesize that the presence of HIV-1 proteins and hypoxia synergistically augment the development of pulmonary vascular dysfunction and PH. We examined the effect of HIV-1 proteins on pulmonary vascular resistance by measuring pressure-volume relationships in isolated lungs from wild-type (WT) and HIV-1 Transgenic (Tg) rats. WT and HIV-1 Tg rats were exposed to 10% O2 for four weeks to induce experimental pulmonary hypertension to assess whether HIV-1 protein expression would impact the development of hypoxia-induced PH. Our results demonstrate that HIV-1 protein expression significantly increased pulmonary vascular resistance (PVR). HIV-1 Tg mice demonstrated exaggerated pulmonary vascular responses to hypoxia as evidenced by greater increases in right ventricular systolic pressures...

Estimation of pulmonary vascular resistance: correlation between echocardiography and catheterization data in patients with congenital heart disease

Bhatt, Dheeraj Deo; Manoj, Rohit; Mahajan, Rajiv
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
66%
BACKGROUND: The ratio of peak tricuspid regurgitation velocity (TRV) and right ventricular outflow time–velocity integral (TVI RVOT) has been described as a good correlate of pulmonary vascular resistance (PVR). However, this method has not been well studied in congenital heart disease. METHOD: Twenty patients with post-tricuspid shunt lesions who were planned to undergo cardiac catheterization were enrolled for the study. The ratio of TRV/TVIRVOT was measured via transthoracic echocardiography and correlated with invasively derived PVR (PVRCATH). PVRCATH was measured by cardiac catheterization. Fick’s principle was used to calculate the pulmonary blood flow and oxygen consumption was assumed. Linear regression analysis was done to find the correlation between TRV/TVIRVOT and PVRCATH. RESULTS: There was a significant correlation between the two variables, r = 0.635(P = 0.003). Subgroup analysis revealed that this correlation was better at lower values of PVRCATH (r = 0.817 for PVR < 6 Wood units (WU)) than higher values (r = 0.659 for PVR > 6 WU). TRV/TVIRVOT ratio of greater than 0.145 predicted with 80% sensitivity and specificity a PVR > 6 WU. CONCLUSIONS: There is modest correlation between TRV/TVIRVOT ratio and invasively derived PVR in congenital shunt lesions...

Lowering Pulmonary Wedge Pressure after Heart Transplant: Pulmonary Compliance and Resistance Effect

Moreira,Nádia; Baptista,Rui; Costa,Susana; Franco,Fátima; Pêgo,Mariano; Antunes,Manuel
Fonte: Sociedade Brasileira de Cardiologia - SBC Publicador: Sociedade Brasileira de Cardiologia - SBC
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2015 EN
Relevância na Pesquisa
55.93%
AbstractBackground:Right ventricular (RV) afterload is an important risk factor for post-heart transplantation (HTx) mortality, and it results from the interaction between pulmonary vascular resistance (PVR) and pulmonary compliance (CPA). Their product, the RC time, is believed to be constant. An exception is observed in pulmonary hypertension because of elevated left ventricular (LV) filling pressures.Objective:Using HTx as a model for chronic lowering of LV filling pressures, our aim was to assess the variations in RV afterload components after transplantation.Methods:We retrospectively studied 159 patients with right heart catheterization before and after HTx. The effect of Htx on hemodynamic variables was assessed.Results:Most of the patients were male (76%), and the mean age was 53 ± 12 years. HTx had a significant effect on the hemodynamics, with normalization of the LV and RV filling pressures and a significant increase in cardiac output and heart rate (HR). The PVR decreased by 56% and CPA increased by 86%. The RC time did not change significantly, instead of increasing secondary to pulmonary wedge pressure (PWP) normalization after HTx as expected. The expected increase in RC time with PWP lowering was offset by the increase in HR (because of autonomic denervation of the heart). This effect was independent from the decrease of PWP.Conclusion:The RC time remained unchanged after HTx...

Estimation of pulmonary vascular resistance: correlation between echocardiography and catheterization data in patients with congenital heart disease

Deo Bhatt, D.; Manoj, R.; Mahajan, R.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
66%
Background: The ratio of peak tricuspid regurgitation velocity (TRV) and right ventricular outflow time–velocity integral (TVI RVOT) has been described as a good correlate of pulmonary vascular resistance (PVR). However, this method has not been well studied in congenital heart disease. Method: Twenty patients with post-tricuspid shunt lesions who were planned to undergo cardiac catheterization were enrolled for the study. The ratio of TRV/TVIRVOT was measured via transthoracic echocardiography and correlated with invasively derived PVR (PVRCATH). PVRCATH was measured by cardiac catheterization. Fick's principle was used to calculate the pulmonary blood flow and oxygen consumption was assumed. Linear regression analysis was done to find the correlation between TRV/TVIRVOT and PVRCATH. Results: There was a significant correlation between the two variables, r = 0.635(P = 0.003). Subgroup analysis revealed that this correlation was better at lower values of PVRCATH (r = 0.817 for PVR < 6 Wood units (WU)) than higher values (r = 0.659 for PVR > 6 WU). TRV/TVIRVOT ratio of greater than 0.145 predicted with 80% sensitivity and specificity a PVR > 6 WU. Conclusions: There is modest correlation between TRV/TVIRVOT ratio and invasively derived PVR in congenital shunt lesions...

Blockade of the action of nitric oxide in human septic shock increases systemic vascular resistance and has detrimental effects on pulmonary function after a short infusion of methylene blue

Weingartner, Roger; Oliveira, E.; Oliveira, Elizabeth dos Santos Boos de; Sant'Anna, Urbano Leonel; Oliveira, Rodrigo Pereira de; Azambuja, L. A.; Friedman, Gilberto
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
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To investigate the role of nitric oxide in human sepsis, ten patients with severe septic shock requiring vasoactive drug therapy and mechanical ventilation were enrolled in a prospective, open, non-randomized clinical trial to study the acute effects of methylene blue, an inhibitor of guanylate cyclase. Hemodynamic and metabolic variables were measured before and 20, 40, 60, and 120 min after the start of a 1-h intravenous infusion of 4 mg/kg of methylene blue. Methylene blue administration caused a progressive increase in mean arterial pressure (60 [55-70] to 70 [65-100] mmHg, median [25-75th percentiles]; P<0.05), systemic vascular resistance index (649 [479-1084] to 1066 [585-1356] dyne s-1 cm-5 m-2; P<0.05) and the left ventricular stroke work index (35 [27-47] to 38 [32-56] g m-1 m-2; P<0.05) from baseline to 60 min. The pulmonary vascular resistance index increased from 150 [83-207] to 186 [121-367] dyne s-1 cm-5 m-2 after 20 min (P<0.05). Mixed venous saturation decreased from 65 [56-76] to 63 [55-69]% (P<0.05) after 60 min. The PaO2/FiO2 ratio decreased from 168 [131-215] to 132 [109-156] mmHg (P<0.05) after 40 min. Arterial lactate concentration decreased from 5.1 ± 2.9 to 4.5 ± 2.1 mmol/ l, mean ± SD (P<0.05) after 60 min. Heart rate...