• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.395-406
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• 2000

The present study was conducted to examine the developmental capacity of mouse oocytes within prenatal follicles cultured various concentrations of FSH and LH and the expression of cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) and cytochrome P450 17 $\alpha$ -hydroxylase (P450)$_{17{\alpha}}$ mRNA, as luteinization and atretic marker, in these culture conditions. In addition, we investigated the concentrations of progesterone and testosterone in culture medium. The developmental potential up to blastocyst of the oocytes grown in vitro was higher in the FSH alone (30.2%) and 10 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated (28.0%) groups than in the 100 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated group (22.0%). And the mean numbers of cell per blastocyst was higher in the FSH alone (50.9$\pm$26.1) and 10 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated (51.0$\pm$21.1) groups when compared to the 100 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated group (45.2$\pm$15.1). The expressions of P450scc and P450$_{17{\alpha}}$ mRNA in the oocyte -cumulus complexes were increased with increasing of LH concentration, and also the secretions of progesterone and testosterone were increased. Especially, in the 100 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH treated group, the expression of P450scc and P450$_{17{\alpha}}$ were significantly increased, and the secretion of progesterone and testosterone were significantly increased. Therefore, these data show that gonadotrophins are essential for the in vitro culture of preantral follicles, but that increasing of LH concentration is reduced the developmental capacity of oocytes. The cause of these findings may be due to increasing of progesterone and testosterone secretion by the enhance of P450scc and P450$_{17{\alpha}}$ mRNA expressions, as markers of luteinization and atresia. Conclusively, this study suggest that supplementation of 100 $m\ell$U/$m\ell$ FSH or 10 $m\ell$U/$m\ell$ LH and 100 $m\ell$U/$m\ell$ FSH may be optimal condition for the culture of mouse pre antral follicles.