The Effect of Hypoxanthine on Mouse Oocyte Growth and Development in Vitro: Maintenance of Meiotic Arrest and Gonadotropin-Induced Oocyte Maturation

Dev Biol. 1987 Feb;119(2):313-21. doi: 10.1016/0012-1606(87)90037-6.

Abstract

The concentration of hypoxanthine in mouse follicular fluid has been estimated to be 2-4 mM, and although this concentration maintains meiotic arrest in fully grown mouse oocytes in vitro, oocyte maturation in vivo is not induced by a decrease in the concentration of this purine in follicular fluid (J. J. Eppig, P. F. Ward-Bailey, and D. L. Coleman, Biol. Reprod. 33, 1041-1049, 1985). In the present study, the effect of 2 mM hypoxanthine on oocyte growth and development in vitro was assessed and the ability of gonadotropins to stimulate oocyte maturation in the continued presence of hypoxanthine was determined. Oocyte-granulosa cell complexes were isolated from 10- to 11-day-old mice and cultured in the presence or absence of 2 mM hypoxanthine. Oocytes from 10- to 11-day-old mice are in mid-growth phase and, without further development, are incompetent of undergoing meiotic maturation. During a 12-day culture period the granulosa cell-enclosed oocytes approximately doubled in size and, regardless of the presence or absence of hypoxanthine, 50-70% developed competence to undergo germinal vesicle breakdown (GVBD). Hypoxanthine promoted the continued association of oocytes with their companion granulosa cells during the 12-day culture period, and therefore had a beneficial effect on oocyte development. Most of the oocytes that acquired GVBD competence in the absence of hypoxanthine underwent spontaneous GVBD. In contrast, 95% of the GVBD-competent oocytes were maintained in meiotic arrest by hypoxanthine. Following withdrawal of the hypoxanthine after the 12-day culture, 75% of the GVBD-competent oocytes underwent GVBD. These results show that hypoxanthine, and/or its metabolites, maintains meiotic arrest in oocytes that grow and acquire GVBD competence in vitro. Follicle-stimulating hormone (FSH), but not luteinizing hormone or human chorionic gonadotropin, induced oocyte GVBD in the continued presence of hypoxanthine. FSH stimulated oocyte maturation at a significantly (P less than 0.01) higher frequency than coculture of the granulosa cell-denuded oocytes with granulosa cells in the continued presence of hypoxanthine. FSH did not induce the maturation of denuded oocytes cocultured with granulosa cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cells, Cultured
  • Chorionic Gonadotropin / pharmacology
  • Female
  • Follicle Stimulating Hormone / pharmacology
  • Granulosa Cells / physiology
  • Hypoxanthine
  • Hypoxanthines / pharmacology*
  • Luteinizing Hormone / pharmacology
  • Meiosis / drug effects*
  • Mice
  • Mice, Inbred C57BL
  • Oocytes / drug effects
  • Oocytes / growth & development*

Substances

  • Chorionic Gonadotropin
  • Hypoxanthines
  • Hypoxanthine
  • Luteinizing Hormone
  • Follicle Stimulating Hormone