CARDIOVASCULAR EFFECTS OF LONG-TERM ENDOTHELIN INFUSION AND RESPONSES TO ENDOTHELIN DURING ACTH INFUSION IN CONSCIOUS SHEEP

被引:9
作者
MAY, CN
MATHAI, ML
MCDOUGALL, JG
WHITWORTH, JA
机构
[1] Howard Florey Institute of Experimental Physiology and Medicine University of Melbourne, Parkville
[2] Department of Medicine, St. George Hospital, University of New South Wales
基金
英国医学研究理事会;
关键词
CORTICOTROPIN; BLOOD PRESSURE; CARDIAC OUTPUT; ENDOTHELIN; SHEEP;
D O I
10.1093/ajh/6.10.837
中图分类号
R6 [外科学];
学科分类号
1002 ; 100210 ;
摘要
Infusion of endothelin-1 (ET-1) (2000 pmol/h) into conscious sheep for 6 days caused a sustained increase in mean arterial pressure (MAP) of 19 +/- 1 mm Hg. This response was mediated by the vasoconstrictor effect of ET-1 and was accompanied by a fall in cardiac output. Plasma renin concentration fell throughout the infusion and atrial natriuretic peptide was increased on day 1 of ET-1 infusion. Hematocrit dramatically increased, probably mainly due to plasma loss resulting from the ET-1-induced increased capillary hydrostatic pressure. To determine whether increased pressor responsiveness to ET-1 played a role in the rise in MAP caused by corticotropin (ACTH), the responses to bolus doses of ET-1 were evaluated before ACTH and on days 3 and 5 of ACTH infusion (5 mug/kg/day). ACTH increased MAP from 71 +/- 2 to 87 +/- 3 mm Hg. On the control day ET-1 (400, 1200, and 2000 pmol) increased MAP by 5 +/- 1, 18 +/- 6 and 35 +/- 11 mm Hg, respectively. No initial vasodilation occurred. The responses to all doses of ET-1 were similar during ACTH infusion. Plasma levels of ET-1 did not increase during ACTH infusion. These results demonstrate that long-term infusion of ET-1 caused a sustained increase in blood pressure. There was no evidence that the sensitivity or responsiveness to ET-1 were altered during infusion of ACTH. In conclusion, ET-1 could play a role in the pathogenesis of hypertension but does not appear to be involved in the increase in blood pressure caused by ACTH.
引用
收藏
页码:837 / 843
页数:7
相关论文
共 30 条
[1]  
Yanagisawa M., Kurihara H., Kimura S., Et al., A novel potent vasoconstrictor peptide produced by vascular endothelial cells, Nature, 332, pp. 411-115, (1988)
[2]  
Hinojosa-Laborde C., Osborn J.W., Cowley A.W., Hemodynamic effects of endothelin in conscious rats, Am Physiol, 256, pp. H1742-H1746, (1989)
[3]  
Nakamoto H., Suzuki H., Murakami M., Et al., Effects of endothelin on systemic and renal haemodynamics and neuroendocrine hormones in conscious dogs, Clin Sci, 77, pp. 567-572, (1989)
[4]  
Hughes A.D., Human vascular responses to endothelin-1. Observations in vivo and in vitro, J Cardiovasc Pharmacol, 13, pp. S225-S228, (1989)
[5]  
Reid A.F., Parkes D.G., Coghlan J.P., Et al., Haemodynamic effects of long-term endothelin infusion in conscious sheep, Clin Exp Pharmacol Physiol, 17, pp. 241-245, (1990)
[6]  
Yokokawa K., Kohno M., Murakawa K., Et al., The effects of endothelin on blood pressure and renal hemodynamics in DOCA-salt hypertensive rats under conscious and unrestained condition, Clin Exp Hypertens, A12, pp. 1049-1062, (1990)
[7]  
Carvalho M., Nigro D., Scivoletto R., Et al., Comparison of the effect of endothelin on microvessels and macrovessels in Goldblatt II and deoxycorticosterone acetate-salt hypertensive rats, Hypertension, 15, pp. 168-171, (1990)
[8]  
Spence C.D., Brown A., Coghlan J.P., Et al., Rapid haemodynamic response to adrenocorticotrophin and the role of peripheral resistance in adrenocorticotrophin- induced hypertension in conscious sheep, J Hypertens, 7, pp. 277-285, (1989)
[9]  
Parkes D.G., Reid A.F., Coghlan J.P., Et al., Effects of calcium channel blockade on the haemodynamic responses to endothelin infusion in conscious sheep, Am J Hypertens, 4, pp. 719-722, (1991)
[10]  
Scoggins B.A., Allen K., Coghlan J.P., Et al., Haemodynamics of ACTH-induced hypertension in sheep, Clin Sci, 57, pp. 333s-336s, (1979)