Cerebrovascular effects of NG-nitro-L-arginine methylester are conserved under halothane anaesthesia.
The effects of the nitric oxide synthesis inhibitor NG-nitro-L-arginine methylester (L-NAME) on mean arterial blood pressure (MABP) and local cerebral blood flow were determined in conscious and halothane-anaesthetised rats. Thirty minutes post-drug administration in conscious rats L-NAME (30 mg kg-1 i.v.) induced significant hypertension (MABP 132 +/- 2 mmHg and 163 +/- 6 mmHg (means +/- S.D.) for saline and L-NAME groups respectively) and significant hypoperfusion throughout the brain (mean +/- S.D. reduction in cerebral blood flow 27.3 +/- 5.9% compared with controls). In contrast, under halothane anaesthesia, L-NAME did not significantly change MABP but significant reductions in cerebral blood flow (43.2 +/- 3.7%) were observed. Thus the cerebrovascular response to L-NAME is conserved under halothane anaesthesia despite attenuation of the peripheral vasoconstrictive action.
Dawson
D A
DA
University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, UK.
McCulloch
J
J
Macrae
I M
IM
D000769:Anesthesia, Inhalation; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D006221:Halothane / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009569:Nitric Oxide; D001120:Arginine; D006221:Halothane; D019331:NG-Nitroarginine Methyl Ester