Perinatal history of hypoxia leads to lower vascular pressures and hyporeactivity to angiotensin II in isolated lungs of adult rats

Title:

Perinatal history of hypoxia leads to lower vascular pressures and hyporeactivity to angiotensin II in isolated lungs of adult rats

Creator:

Václav Hampl, Jana Bíbová, and Jan Herget

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:19b1293f-d626-42d7-9008-8539f566395a
uuid:19b1293f-d626-42d7-9008-8539f566395a
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, plicní oběh, pulmonary circulation, perinatal hypoxia, vascular pressure, anginotensin II, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

The most dramatic changes in pulmonary circulation occur at the time of birth. We hypothesized that some of the effects of perinatal hypoxia on pulmonary vessels are permanent. We studied the consequences of perinatal exposure to hypoxia (12 % O2 one week before and one week after birth) in isolated lungs of adult male rats (~12 weeks old) perfused with homologous blood. Perfusion pressure-flow relationship was tilted towards lower pressures in the perinatally hypoxic as compared to the control, perinatally normoxic rats. A non-linear, distensible vessel model analysis revealed that this was due to increased vascular distensibility in perinatally hypoxic rats (4.1±0.6 %/mm Hg vs. 2.3±0.4 %/mm Hg in controls, P = 0.03). Vascular occlusion techniques showed that lungs of the perinatally hypoxic rats had lower pressures at both the pre-capillary and post-capillary level. To assess its role, basal vascular tone was eliminated by a high dose of sodium nitroprusside (20 µM). This reduced perfusion pressures only in the lungs of rats born in hypoxia, indicating that perinatal hypoxia leads to a permanent increase in the basal tone of the pulmonary vessels. Pulmonary vasoconstrictor reactivity to angiotensin II (0.1-0.5 µg) was reduced in rats with the history of perinatal hypoxia. These data show that perinatal hypoxia has permanent effects on the pulmonary circulation that may be beneficial and perhaps serve to offset the previously described adverse consequences., V. Hampl, J. Bíbová, J. Herget., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2000 Volume:49 | Number:5

Harvested from:

CDK

Metadata only:

false