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THE EFFECTS OF SAR 1 ALA 8 ‐ANGIOTENSIN II IN VASOPRESSIN‐TREATED DEHYDRATED SHEEP
Author(s) -
Kelly Catherine,
Wholohan Therese,
Yesberg Nancy E.
Publication year - 1983
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0144-8757
DOI - 10.1113/expphysiol.1983.sp002708
Subject(s) - vasopressin , radiochemistry , chemistry , angiotensin ii , medicine , biochemistry , receptor
Mildly dehydrated conscious Merino ewes were infused with vasopressin (AVP) at 5 mu.min −1 alone and simultaneously with the angiotensin II receptor blocker sar 1 ala 8 ‐angiotensin II (saralasin) at 15 µg.min −1 . AVP was slightly pressor and produced an increase in the calculated total peripheral resistance, and an increase in glomerular filtration rate, urine flow and electrolyte excretion, without a change in total renal plasma flow. These results indicate renal efferent arteriolar vasoconstriction as well as other non‐renal vasoconstriction. Saralasin infusion checked the rise in total peripheral resistance (which continued to increase after saralasin withdrawal), but caused a marked increase in renal vascular resistance resulting in a decrease in renal plasma flow and to a lesser extent in glomerular filtration rate. These results suggest that saralasin was acting as an angiotensin II agonist in the kidney, but as an antagonist elsewhere. Deductions from previous experiments in the literature of the renal function of angiotensin II, based on its supposed inhibition by saralasin, may not be justified.