Nitric oxide synthase inhibition is detrimental to cardiac function and promotes bronchospasm in anaphylaxis in rabbits.
We studied the effects of a nitric oxide synthase (NOS) inhibitor, N omega-nitro-L-arginine-methyl ester (L-NAME), on cardiac depression and bronchospasm provoked by systemic anaphylaxis in vivo in rabbits. Animals pretreated with L-NAME showed lower survival rates than control animals pretreated with normal saline. The survival rate in L-NAME-pretreated animals was increased by the administration of L-arginine after initiation of anaphylaxis. Cardiac output fell significantly in animals pretreated with L-NAME compared with controls, although venous return was increased. In animals pretreated with L-NAME, pulmonary resistance was significantly increased, and administration of arginine attenuated the bronchospasm. In conclusion, these results, along with the low survival rates in the L-NAME-treated animals, suggest that NO production may be beneficial to cardiac depression and bronchospasm in anaphylaxis in vivo.
D000704:Analysis of Variance; D000707:Anaphylaxis / Q000150:complications*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D001986:Bronchial Spasm / Q000139:chemically induced*; D003864:Depression, Chemical; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D011817:Rabbits; D011897:Random Allocation; D015996:Survival Rate
D004791:Enzyme Inhibitors; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester