The Effects of Volatile Anesthetics and Narcotics on In Vitro Fertilization of Mouse Oocytes

Kim, Jong Hak; Lee, Choon Hi

Abstract

Anesthesia is prerequisite to assisted reproductive technologies such as in vitro fertilization and embryo transfer(IVF-ET) and gamete intrafaUopian transfer(GIFT). When choosing the anesthetic agents to facilitate laparoscopic transfer of oocytes and sperms during GIFT procedures and transvaginal ultrasonographic harvesting of oocytes, it is essential to rule out adverse effects of these drugs on fertilization and subsequent development. Unfortunately very little information is available to ascertain if any of the various anesthetics used in these procedures are toxic to the oocyte and developing preimplantation embryo. The purpose of these studies was undertaken to investigate the effects of volatile anesthetics and narcotics on the fertilization and early development of embryos using in vitro fertilization model of mouse oocytes. In the first experiment, mouse oocytes obtained from Fl hybrid(C57BL6 X CBA) were randomly exposed to three volatile anesthetics, enflurane(0.5 mM;1.5 mM), isoflurane(0.26 mM; 0.78 mM) and halothane(0.24 mM;0.72 mM),and in the second experiment they were exposed to two narcotics, meperidine(1.0 uM; 3.6 uM) and fentanyl(6.0 nM: 30.0 nM) respectively. In both experiments mouse oocytes unexposed to any drugs were served as controls. In vitro developmental patterns were observed on the first, fourth and sixth day after insemination of above oocytes. The results were as follows. 1) Any volatile anesthetics studied had no effect on the cleavage rate of mouse oocytes on the first day after insemination, but the incidence of degenerative and fragmented oocytes in 0.78 mM isoflurane group increased significantly compared with control. 2) The rates of mouse embryos developed over morula stages on the fourth day after insemination were significantly lower in 0.78 mM isoflurane and halothane group than in control. The rates of embryos arrested at 3-8 cell stage in these groups were significantly greater than that of control. 3) The percentages of mouse oocytes developed to blastocysts on the sixth day after insemiation decreased significantly in 0.78 mM isoflurane and 0.72 mM halothane group compared with control. 4) The hatching rate of blastocysts developed from mouse aocytes preexposed to 0.72 mM halothane was significantly lower than that of control, but the proportions of hatching and hatched blastocysts among total blastocysts were significantly greater in 0.5 mM enflurane and 0.26 mM isoflurane group than in control. 5) Mouse oocytes preexposed to narcotics had a rate of degeneration and cleavage comparable to that in control on the first day after insemination.Also no significant differences in the rates of embryos arrested at 3-8 cell stage on the fourth day after insemination were notecL 6) There were no significant differences in blastocysts developrnent and their hatching on the sixth day after insemination between the groups preexposed to either fentanyl or meperidine and control. In conclusion these results indicate that narcotics, fentanyl and meperidine does not show adverse effects on in vitro fertilization of mouse oocytes in concentrations calculated to approximate those to which human ova would be exposed during clinical anesthesia and that volatile anesthetics such as isoflurane and halothane is detrimental to in vitro fertilization of mouse oocytes in high concentrations.