Otsuka A, Mikami H, Katahira K, Tsunetoshi T, Minamitani K, Ogihara T
Department of Geriatric Medicine, Osaka University Medical School, Japan.
Acta Endocrinol (Copenh). 1989 Sep;121(3):361-4. doi: 10.1530/acta.0.1210361.
The effects of endothelin on the renin-aldosterone system were examined by injecting it intravenously at low (40 pmol/kg) and high (400 pmol/kg) doses into pentobarbital-anesthetized dogs. Plasma renin activity and aldosterone concentration together with hemodynamic parameters were measured before and 60 min after endothelin injection. The lower dose of endothelin induced no significant increase in mean blood pressure or total peripheral resistance. It caused a slight decrease of plasma renin activity from 10.3 +/- 1.6 to 5.9 +/- 1.3 micrograms.l-1.h-1 (p less than 0.1) and a decrease of aldosterone concentration from 364 +/- 68 to 231 +/- 58 ng/l (p less than 0.05) with an increase in total peripheral resistance (p less than 0.05), but it did not cause any clear change in the plasma renin activity or aldosterone concentration. Thus, endothelin increases the blood pressure mainly by vasoconstriction. The finding of a slight decrease in the plasma renin activity after the lower dose of endothelin, together with our previous finding that endothelin inhibits renin release from isolated rat glomeruli, suggests that endothelin inhibits renin release in vivo. With the higher dose of endothelin, stimulation of renin release secondary to renal vasoconstriction might have counteracted the direct inhibitory action of endothelin. The decrease in aldosterone concentration may have been due to the direct inhibitory action of endothelin on aldosterone release or it may be a secondary effect induced by suppression of plasma renin activity.
通过向戊巴比妥麻醉的犬静脉内注射低剂量（40 pmol/kg）和高剂量（400 pmol/kg）的内皮素，研究了内皮素对肾素 - 醛固酮系统的影响。在内皮素注射前和注射后60分钟测量血浆肾素活性、醛固酮浓度以及血流动力学参数。较低剂量的内皮素未引起平均血压或总外周阻力的显著增加。它使血浆肾素活性从10.3±1.6微 克·升⁻¹·小时⁻¹轻微降低至5.9±1.3微 克·升⁻¹·小时⁻¹（p<0.1），醛固酮浓度从364±68纳克/升降低至231±58纳克/升（p<0.05），同时总外周阻力增加（p<0.05），但未引起血浆肾素活性或醛固酮浓度的任何明显变化。因此，内皮素主要通过血管收缩升高血压。较低剂量内皮素注射后血浆肾素活性轻微降低的发现，连同我们之前发现内皮素抑制离体大鼠肾小球肾素释放，提示内皮素在体内抑制肾素释放。使用较高剂量的内皮素时，肾血管收缩继发的肾素释放刺激可能抵消了内皮素的直接抑制作用。醛固酮浓度的降低可能是由于内皮素对醛固酮释放的直接抑制作用，或者可能是血浆肾素活性受抑制所诱导的继发效应。
