Regulation of adrenal vascular tone: role of endothelin-1 and nitric oxide.
The adrenal gland is a highly vascular organ, with a highly conserved and well-regulated blood supply. This study was designed to determine the roles of the local vascular regulators, nitric oxide (NO) and endothelin-1 (ET-1), in the regulation of adrenal vascular tone. Using the in situ intact perfused rat adrenal preparation it was found that the ETA receptor antagonist, BQ123, caused a significant increase in perfusion medium flow rate, while the ETB antagonist, RES-701-1, had no effect. Administration of the NO synthesis, inhibitor, L-NAME, or perfusing medium lacking the substrate for NO synthesis, resulted in a significant decrease in perfusion medium flow rate through the adrenal gland. These results suggest that endogenous endothelin causes a tonic vasoconstriction in the rat adrenal gland, mediated by the ETA receptor and that endogenous NO exerts a tonic vasodilatory effect on the rat adrenal.
Hinson
J P
JP
Department of Biochemistry (BMS), Queen Mary and Westfield College, London.
Cameron
L A
LA
Kapas
S
S
D000311:Adrenal Glands / Q000098:blood supply*; D000818:Animals; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010456:Peptides, Cyclic / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D010456:Peptides, Cyclic; C087120:RES 701-1; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C072247:cyclo(Trp-Asp-Pro-Val-Leu); D019331:NG-Nitroarginine Methyl Ester