흰쥐에서 내독소 존재하에서의 Ketamine 의 흉부대동맥 절편에 대한 효과 = Effects of Ketamine on the Contractile Response of Endotoxin Exposured Strips of Rat Thoracic Aortic Rings

다국어 초록 (Multilingual Abstract)

Background; Ketamine is often used for induction and mainternance of anesthesia in shock patients. And Ketamine has relaxation effect on vascular endothelium. The effect of NOS inhibitors (L-NAME, aminoguanidine) were evaluated in the strips of thoracic aorta of rat with or without LPS (Esherichia coli lypopolysaccaride) treatment.
Methods: Each ring of aortic arteries was suspended on wire supports in a 20 ml tissue bath under 2 gr of resting tension and incubated with LPS for 4 hours. All tissues were bathed in Tris Tyrode solution at 37℃ and 100% oxygen was supplied. The effects of ketamine, L-NAME, aminoguanidine, methylene blue and indomethacine on contractile responses of aortic rings to phenylephrine (PE) with or without LPS were evaluated respectively.
Results: Without LPS incubation, ketamine 10^-3 M inhibited contraction of aortic rings with PE significantly (P < 0.05). And this relaxation was not recovered with L-NAME pretreatment. With LPS incubation, ketamine 10^-3 M inhibited contraction of aortic rings with PE significantly (P < 0.05). And this relaxation effect was increased compared to the aortic rings without LPS incubation. It was recovered with L-NAME (P < 0.05), aminoguanitidine or methylene blue pretreatments respectivly. But indomethacine enhanced the relaxation effect of ketamine.
Conclusions: The relaxation effect of ketamine is endothelium nondependent. However it is NO dependent and in part, cyclooxygenase inhibition and guanylate cyclase activation are related with this relaxation effect in LPS incubated rings. Both intracellular calcium efflux and extracelluar calcium influx are inhibited with ketamine in these rings.