Induction in vitro of mucification of rat cumulus oophorus by gonadotrophins and adenosine 3',5'-monophosphate.

In this study, the ability of LH in vitro to induce the intercellular mucification which occurs in vivo just before ovulation, has been observed. The test was to measure the ability of bovine testicular hyaluronidase (1 mg/ml) to lyse the cumulus mass. Isolated cumulus-oocyte complexes were cultured for 24 h in the presence of LH, FSH, hCG, one of four cAMP derivatives, or three phosphodiesterase inhibitors. All were shown to be capable of inducing mucification. Timing of the mucification response to FSH and LH was made by examining cultures at hourly intervals. In the presence of 10 μg/ml NIH-LH-B9, mucification appeared after a latent period of 4 h; maximal occurrence of mucification was at 16 h, and half-maximal was at 6.25 h. In cultures incubated with NIH-FSH-Sll, these times were 6.0, 19.0, and 9.25 h, respectively. Times for 0%, 50%, and 100% response were 4.0, 6.25, and 16.0 h for LH and 6.0, 9.25, and 19.0 h for FSH. From analysis of the doseresponse relationship for LH, the ED was found to be 2....