Role of nitric oxide in adrenocorticotrophin-induced hypertension: L-arginine effects reversed by N-nitro-L-arginine.
1. L-arginine prevents adrenocorticotrophin (ACTH)-induced hypertension in the rat. To confirm that this effect is mediated through the nitric oxide (NO) system, we examined whether N-nitro-L-arginine (NOLA) could reverse the L-arginine-induced blockade of ACTH-induced hypertension. 2. Blood pressure and metabolic parameters were examined in sham-, ACTH-, L-arginine + sham-, NOLA + sham-, ACTH + L-arginine- and ACTH + L-arginine + NOLA-treated Sprague-Dawley rats (n = 40). 3. Adrenocorticotrophin treatment increased systolic blood pressure (SBP), water intake and urine output and decreased bodyweight. N-Nitro-L-arginine alone increased SBP without affecting metabolic variables. L-Arginine alone did not affect blood pressure. The SBP was lower in L-arginine + ACTH- than ACTH-treated rats (P < 0.001), but was higher following ACTH + L-arginine + NOLA than ACTH + L-arginine (P < 0.05). 4. N-Nitro-L-arginine reversed the blood pressure-lowering effect of L-arginine in ACTH-induced hypertension in the rat, supporting the notion that NO plays a role in the hypertension.
Wen
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Department of Medicine, St George Hospital, The University of New South Wales, Sydney, Australia.
Li
M
M
Whitworth
J A
JA
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D001120:Arginine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004326:Drinking; D004435:Eating; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006973:Hypertension / Q000139:chemically induced* / Q000503:physiopathology; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D052250:Nitric Oxide Synthase Type III; D019335:Nitroarginine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D004791:Enzyme Inhibitors; D019335:Nitroarginine; D009569:Nitric Oxide; D000324:Adrenocorticotropic Hormone; D001120:Arginine; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat