The Vascular Effect of Ketamine Hydrochloride on The Isolated Rabbit Pulmonary ArteryC / 대한마취과학회지

ABSTRACT

Ketamine hydrochloride is a phencyclidine derivatives and dissociative anesthetics. Ketamine induce the pulmonary vasoconetrietion in vivo. This study was designed to deter- mine the direct effect of the ketamine on the rabbit pulmonary artery in vitro. Isolated pulmonary artery was precontracted with norepinephrine (NE) 10-7M in the 20 ml organ bath. Concentration of ketamine was gradually increased 10-5M, 10 4M and 10-3M at 10 minutes intervals. I divided forty three experimental speeimens into 5 groups pulmonary artery with and without endothelium, pretreated with indomethacin, nitrow-L-arginine methyl ester(L-NAME) and methylene blue. The results were as follows 1. Norepinephrine precontracted pulmonary arterial tone wss significantly decreased by ketamine(10-3M), and the relaxing percent were 81.0 19.3, 60.6 55.4 (Mean S.D.) in unrubbed and rubbed endothelium, respectively (p<0.05). 2. The changes of vascular tone in denuding and intact groups were not significantly different. 3. Vasorelaxation induced by ketamine was not related with nitric oxide(NO) synthase, cyclooxygenase and soluble guanylate cyclase. Ketamine induce relaxation of the rabbit pulmonary artery, especially at 10-3 M concentra- tion. The relaxing effect was not related with endothelium presence, nitric oxide synthase, cyclooxygenase and soluble guanylate cyclase pathways. This data suggest that the relaxing effect of ketamine was not associated with endothelium, Nitric oxide, prostacyclin and cyclic guanosinemonophosphate.