清醒犬急性低氧性肺血管收缩会降低肾素水平，且不受氯沙坦影响。

Acute hypoxic pulmonary vasoconstriction in conscious dogs decreases renin and is unaffected by losartan.

作者信息

Krebs M O, Boemke W, Simon S, Wenz M, Kaczmarczyk G

机构信息

Experimental Anesthesia, Clinic of Anesthesiology and Operative Intensive Care Medicine, 13353 Berlin, Germany.

出版信息

J Appl Physiol (1985). 1999 Jun;86(6):1914-9. doi: 10.1152/jappl.1999.86.6.1914.

DOI:10.1152/jappl.1999.86.6.1914

PMID:10368356

Abstract

Acute hypoxic pulmonary vasoconstriction (HPV) may be mediated by vasoactive peptides. We studied eight conscious, chronically tracheostomized dogs kept on a standardized dietary sodium intake. Normoxia (40 min) was followed by hypoxia (40 min, breathing 10% oxygen, arterial oxygen pressures 36 +/- 1 Torr) during both control (Con) and losartan experiments (Los; iv infusion of 100 microg. min-1. kg-1 losartan). During hypoxia, minute ventilation (by 0.9 l/min in Con, by 1.3 l/min in Los), cardiac output (by 0.36 l/min in Con, by 0.30 l/min in Los), heart rate (by 11 beats/min in Con, by 30 beats/min in Los), pulmonary artery pressure (by 9 mmHg in both protocols), and pulmonary vascular resistance (by 280 and 254 dyn. s. cm-5 in Con and Los, respectively) increased. Mean arterial pressure and systemic vascular resistance did not change. In Con, PRA decreased from 4.2 +/- 0.7 to 2.5 +/- 0.5 ng ANG I. ml-1. h-1, and plasma ANG II decreased from 11.9 +/- 3.0 to 8.2 +/- 2.1 pg/ml. The renin-angiotensin system is inhibited during acute hypoxia despite sympathetic activation. Under these conditions, ANG II AT1-receptor antagonism does not attenuate HPV.

摘要

急性低氧性肺血管收缩（HPV）可能由血管活性肽介导。我们研究了八只清醒的、长期气管切开的狗，它们保持标准化的饮食钠摄入量。在对照（Con）实验和氯沙坦实验（Los；静脉输注100μg·min⁻¹·kg⁻¹氯沙坦）中，先进行40分钟的常氧状态，然后进行40分钟的低氧状态（呼吸10%氧气，动脉血氧分压36±1 Torr）。在低氧期间，分钟通气量（Con组增加0.9 l/min，Los组增加1.3 l/min）、心输出量（Con组增加0.36 l/min，Los组增加0.30 l/min）、心率（Con组增加11次/分钟，Los组增加30次/分钟）、肺动脉压（两个方案中均增加9 mmHg）和肺血管阻力（Con组和Los组分别增加280和254 dyn·s·cm⁻⁵）均升高。平均动脉压和全身血管阻力未改变。在Con组中，肾素活性（PRA）从4.2±0.7降至2.5±0.5 ng ANG I·ml⁻¹·h⁻¹，血浆血管紧张素II（ANG II）从11.9±3.0降至8.2±2.1 pg/ml。尽管交感神经激活，但在急性低氧期间肾素 - 血管紧张素系统受到抑制。在这些条件下，ANG II AT1受体拮抗作用不会减弱HPV。