title: Responsiveness in vitro of porcine luteal tissue recovered at two stages of the luteal phase.
abstract: Corpora lutea (CL) were recovered from pigs at 6 1/2 or 12 1/2 days after induced ovulation and fragments of tissue and isolated cells were incubated for 3 h in vitro. Progesterone synthesis by tissue and cells from 12 1/2-day CL was stimulated by bovine LH (1 micrograms/ml), dibutyryl cyclic AMP (10 mM) and hCG (10-50 i.u./ml) but 6 1/2-day CL, although having a higher level of control synthesis, did not respond to these substances. The addition of testosterone (100 ng/ml) to the incubations was found to suppress the response to bovine LH in the 12 1/2 day tissue and cells. Separation of the dissociated luteal cells into populations of large and small sized cells demonstrated that the large cells were more synthetically active than the small cells, but cells of both sizes in the 12 1/2-day CL responded to bovine LH. These results support the concept that the porcine CL is autonomous for much of its lifespan.
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D003338:Corpus Luteum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D010062:Ovulation Induction; D011374:Progesterone / Q000096:biosynthesis*; D013552:Swine / Q000502:physiology*
chemical_list: D006063:Chorionic Gonadotropin; D011374:Progesterone