犬颈动脉压力反射对颈动脉化学感受器引起的肾血流动力学和功能变化的调节作用

Modification of carotid chemoreceptor-induced changes in renal haemodynamics and function by carotid baroreflex in dogs.

作者信息

Karim F, al-Obaidi M

机构信息

Department of Physiology, University of Leeds.

出版信息

J Physiol. 1993 Jul;466:599-610.

PMID:8410708

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1175494/

Abstract

Mongrel dogs were anaesthetized with thiopental sodium and chloralose and artificially ventilated. The carotid sinus regions were vascularly isolated and perfused either with arterial or mixed (arterial and venous) blood (PO2, 44.2 +/- 3.3 mmHg, mean +/- S.E.M.) to stimulate the chemoreceptors. Cervical vagosympathetic trunks were ligated and atenolol (2 mg kg-1, I.V.) was given in all dogs and gallamine triethiodide (3 mg kg-1 h-1, I.V.) was given in two dogs. Renal blood flow was measured by an electromagnetic flowmeter, glomerular filtration rate by creatinine clearance, sodium excretion by flame photometry and solute excretion by osmometry. The viability of the preparations was tested by recording total vascular capacitance responses to stimulation of carotid baro- and chemoreceptors. 2. In eleven tests in seven dogs at a constant aortic pressure of 88.9 +/- 2.6 mmHg stimulation of carotid chemoreceptors at a high carotid sinus pressure (194.0 +/- 3.6 mmHg) resulted in significant increases in urine flow of 22.8 +/- 3.0%, urinary sodium excretion of 30.7 +/- 5.2%, fractional sodium excretion of 35.3 +/- 18.6%, osmolar excretion of 17.5 +/- 4.1% and a decrease in free water clearance of 30.8 +/- 3.1% without significant changes in urinary sodium concentration, renal blood flow, glomerular filtration rate, and filtration fraction. 3. In seventeen tests in these seven dogs at a constant aortic pressure of 94.0 +/- 2.2 mmHg, stimulation of carotid chemoreceptor at a low carotid sinus pressure (72.0 +/- 1.3 mmHg) resulted in significant decreases in renal blood flow of 10.6 +/- 2.5%, glomerular filtration rate of 19.6 +/- 6.8%, filtration fraction of 13.2 +/- 5.5%, urine flow of 23.4 +/- 4.1%, urinary sodium concentration of 20.3 +/- 4.1%, urinary sodium excretion of 38.5 +/- 4.6%, fractional sodium excretion of 20.2 +/- 7.7%, osmolar excretion of 23.9 +/- 4.0% and an increase in free water clearance of 23.1 +/- 2.5%. 4. The results show that moderate stimulation of carotid chemoreceptors at a low carotid sinus pressure, when the activity in renal nerves is high and blood volume is low, can produce significant reflex decreases in renal haemodynamic and functional variables. However, at a high carotid sinus pressure when the renal sympathetic activity is low and blood volume is high, carotid chemoreceptor stimulation produces diuresis and natriuresis but no change in renal haemodynamics.

摘要

杂种犬用硫喷妥钠和氯醛糖麻醉并进行人工通气。分离颈动脉窦区域的血管，并用动脉血或混合血（动脉血和静脉血，血氧分压为44.2±3.3 mmHg，均值±标准误）灌注以刺激化学感受器。结扎颈迷走交感干，所有犬均静脉注射阿替洛尔（2 mg/kg），两只犬静脉注射三碘季铵酚（3 mg/kg·h）。用电磁流量计测量肾血流量，用肌酐清除率测量肾小球滤过率，用火焰光度法测量钠排泄量，用渗透压测定法测量溶质排泄量。通过记录对颈动脉压力感受器和化学感受器刺激的总血管容量反应来测试标本的活力。2. 在7只犬的11次试验中，在主动脉压恒定为88.9±2.6 mmHg时，在高颈动脉窦压力（194.0±3.6 mmHg）下刺激颈动脉化学感受器，导致尿流量显著增加22.8±3.0%，尿钠排泄量增加30.7±5.2%，钠排泄分数增加35.3±18.6%，渗透排泄量增加17.5±4.1%，自由水清除率降低30.8±3.1%，而尿钠浓度、肾血流量、肾小球滤过率和滤过分数无显著变化。3. 在这7只犬的17次试验中，在主动脉压恒定为94.0±2.2 mmHg时，在低颈动脉窦压力（72.0±1.3 mmHg）下刺激颈动脉化学感受器，导致肾血流量显著减少10.6±2.5%，肾小球滤过率减少19.6±6.8%，滤过分数减少13.2±5.5%，尿流量减少23.4±4.1%，尿钠浓度增加20.3±4.1%，尿钠排泄量增加38.5±4.6%，钠排泄分数增加20.2±7.7%，渗透排泄量增加23.9±4.0%，自由水清除率增加23.1±2.5%。4. 结果表明，当肾神经活动高且血容量低时，在低颈动脉窦压力下适度刺激颈动脉化学感受器可使肾血流动力学和功能变量产生显著的反射性降低。然而，在高颈动脉窦压力下，当肾交感神经活动低且血容量高时，刺激颈动脉化学感受器会产生利尿和利钠作用，但肾血流动力学无变化。