Corticotrophin releasing factor attenuates NG-nitro-L-arginine methyl ester induced increases in blood pressure in the anaesthetised rat.
In vitro corticotrophin releasing factor (CRF) causes a prolonged endothelium-dependent vasodilatation which is blocked by inhibitors of nitric oxide (NO) synthase (NOS). Here the role of NO in CRF-induced reductions in blood pressure (BP) has been investigated using anaesthetised rats. Infusion of NG-Nitro-L-arginine Methyl Ester (L-NAME) increased mean arterial pressure (MAP) but did not reduce the fall in BP caused by CRF injection. Bolus injection of L-NAME produced a marked vasopressor effect when given alone. However, when administered 20 min after CRF, L-NAME restored MAP to basal levels, but the marked vasopressor response observed in control animals was completely blocked. This indicates that the increase in BP occurring on bolus injection of L-NAME is not simply due to an inhibition of NO-dependent vasodilatation.
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Cellular Pharmacology Group, The William Harvey Research Institute, St Bartholomew's and the Royal London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ, UK.
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D000758:Anesthesia; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004195:Disease Models, Animal; D004347:Drug Interactions; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006973:Hypertension / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000378:metabolism / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D003346:Corticotropin-Releasing Hormone; D019331:NG-Nitroarginine Methyl Ester