Effects of insulin-like growth factor-I on final oocyte maturation and steroid production in Fundulus heteroclitus
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Recent evidence has indicated the presence of IGF-I and IGF-I receptors in mammalian and teleost ovarian follicles. Since growth hormone (GH), which can be secreted from the pituitary concomitant with a gonadotropin as a response to gonadotropin-releasing hormone, generally acts to release IGF-I from tissues including the ovary, the effect of IGF-I itself on ovarian steroidogenesis and oocyte maturation was investigated in the model teleost, Fundulus heteroclitus. IGF-I was found to be without effect on ovarian follicle steroidogenesis, but initiated oocyte maturation in a dose-dependent manner even more rapidly and effectively than 17α,20β-dihydroxy-4-pregnene-3-one (DHP), the naturally occurring maturation-inducing steroid. IGF-II also induced oocyte maturation in a dose-dependent manner. IGF-I induction of oocyte maturation occurred in the absence of DHP production by the granulosa cells (which is normally stimulated by gonadotropin), and could be inhibited by cycloheximide but not actinomycin D, thus implicating the role of protein synthesis. These results suggest that GH-stimulated release of ovarian IGF-I may have an even more direct role than DHP on the reinitiation of oocyte maturation.
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- Duan, C. and Hirano, T. 1990. Stimulation of [35S]sulfate uptake by mammalian insulin-like growth factors I and II in cultured cartilages of the Japanese eel, Anguilla japonica. J. Exp. Zool. 256: 347–350.Google Scholar
- Duan, C., Duguay, S.J. and Plisetskaya, E.M. 1993. Insulin-like growth factor I mRNA expression in coho salmon, Oncorhynchus kisutch: tissue distribution and effects of growth hormone/prolactin family proteins. Fish Physiol. Biochem. 11: 371–379.Google Scholar
- Gutierrez, J., Parrizas, M., Carneiro, N., Maestro, J.L., Maestro, M.A. and Planas, J. 1993. Insulin and IGF-I receptors and tyrosine kinase activity in carp ovaries: Changes with reproductive cycle. Fish Physiol. Biochem. 11: 247–254.Google Scholar
- Maestro, M.A., Planas, J.V., Moriyama, S., Gutierrez, J., Planas, J. and Swanson, P. 1997. Ovarian receptors for insulin and insulin-like growth factor I (IGF-I) and effects of IGF-I on steroid production by isolated follicular layers of the preovulatory coho salmon ovarian follicle. Gen. Comp. Endocrinol. 106: 189–201.CrossRefPubMedGoogle Scholar
- Niu, P.-D. and LeBail, P.-Y. 1993. Presence of insulin-like growth factor binding protein in rainbow trout (Oncorhynchus mykiss) serum. J. Exp. Zool. 265: 627–636.Google Scholar
- Petrino, T.R., Lin, Y.-W.P., Netherton, J.C., Powell, D.H. and Wallace, R.A. 1993. Steroidogenesis in Fundulus heteroclitus V. Purification, characterization, and metabolism of 17α,20β-dihydroxy-4-pregnen-3-one by intact follicles and its role in oocyte maturation. Gen. Comp. Endocrinol. 92: 1–15.CrossRefPubMedGoogle Scholar
- Selman, K. and Wallace, R.A. 1986. Gametogenesis in Fundulus heteroclitus. Am. Zool. 26: 173–192.Google Scholar
- Srivastava, R.K. and Van Der Kraak, G. 1994a. Regulation of DNA synthesis in goldfish vitellogenic ovarian follicles by hormones and growth factors. J. Exp. Zool. 270: 263–272.Google Scholar
- Yamashita, M., Fukada, S., Yoshikuni, M., Bulet, P., Hirai, T., Yamaguchi, A., Lou, Y.H., Zhao, Z. and Nagahama, Y. 1992. Purification and characterization of maturation-promoting factor in fish. Dev. Biol. 148: 8–15.Google Scholar
- Yoshikuni, M., Shibata, N. and Nagahama, Y. 1993. Specific binding of [3H] 17α, 20β-dihydroxy-4-pregnen-3-one to oocyte cortices of rainbow trout (Oncorhynchus mykiss). Fish Physiol. Biochem. 11: 15–24.Google Scholar
- Young, G., Ueda, H. and Nagahama, Y. 1983. Estradiol-17β and 17α,20β-dihydroxy-4-pregnen-3-one production by isolated ovarian follicles of amago salmon (Oncorhynchus rhodurus) in response to mammalian pituitary and placental hormones and salmon gonadotropin. Gen. Comp. Endocrinol. 52: 329–335.CrossRefPubMedGoogle Scholar
- Yu, K.L., Peng, C. and Peter, R.E. 1991. Changes in brain levels of gonadotropin-releasing hormone and serum levels of gonadotropin and growth hormone in goldfish during spawning. Can. J. Zool. 69: 182–188.Google Scholar