1995 Fiscal Year Final Research Report Summary

THE STUDY OF INHIBITORY FACTORS UTERINE CONTRACTION IN PREGNANCY DURING ANESTHESIA.

Research Project

Project/Area Number	06671546
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Anesthesiology/Resuscitation studies
Research Institution	YOKOHAMA CITY UNIVERSITY
Principal Investigator	SEKINO Nagaaki YOKOHAMA CITY UNIVERSITY,SCHOOL OF MEDICINE,DEPARTMENT OF ANESTHSIOLOGY,STAFF, 医学部, 助手 (30226659)
Co-Investigator(Kenkyū-buntansha)	OKUMURA Fukuichiro YOKOHAMA CITY UNIVERSITY,SCHOOL OF MEDICINE,DEPARTMENT OF ANESTHSIOLOGY,PROFESSO, 医学部, 教授 (50028487) ENDOU Masayuki YOKOHAMA CITY UNIVERSITY,SCHOOL OF MEDICINE,DEPARTMENT OF ANESTHSIOLOGY,ASSOCIAT, 医学部, 講師 (90244508)
Project Period (FY)	1994 – 1995
Keywords	uterine smooth nuscle / anesthtics / contraction / oxytocin / PGF_2alpha / uterine pressure / temperature / rat / pregnancy
Research Abstract	We investigated the effects for contraction of uterine smooth muscle strips from late pregnant rats and guinea pigs. Most of preparations showed spontaneously phasic contraction. We could't make the tonic contraction of preparations by oxytosin, PGF_2alpha and high K^+. But, oxytocin and PGF_2alpha increased phasic contraction. PGE_1, clonidine, indomethacin, adenosine, SNP,NTG,ketamine and isoflurane failed the myometrium relax. Isoproterenol and nifedipine showed inhibitory effects of myometrium contraction. The temperature change of organ bath from 25ﾟC to 37ﾟC made spontaneously contraction inhibited in some preparations. From our results, c-AMP rather than c-GMP appears more effective to relax uterine smooth muscle. Next, we carried out in vivo experiment. The pregnant rat was ventilated and cannulated in jugular vein and carotid artery under ether anesthesia. The uterine contraction pressure was monitored by small balloon inserted in uterus instead of one fetus. The uterus constricted phasicly. Epinephrine, methoxythamine, dopamine, dobtamine and OPC18790 didn't influenced on uterine contraction. Isoproterenol decreased the contraction effectively. Halothane and isoflurane failed to relax uterine contraction, but made the rats in catastrophe. The temperature change made the effects on uterine contraction, but detail analysis needed more cases. We understand this in vivo experiments were useful to investigate the uterine contraction, so more refine and more cases need for this method.