Effect of FSH on progesterone secretion by porcine large and small luteal cells isolated from early-developing corpora lutea.

Isolated porcine luteal cells from d 0-3 of the estrous cycle (estrus-d 0) were incubated with or without addition of 0, 10, 10(2) or 10(3) ng FSH/ml. Progesterone (P4) content was determined after 24 hrs of incubation. In nonstimulated conditions the basal P4 production of large cells (LCs) was 65 fold higher than that of small cells (SCs). The LCs but not SCs were stimulated by doses of 10 and 10(2) ng FSH. FSH in doses of 10 and 10(2) ng did not influence P4 production by SCs, but higher doses (10(3) ng) significantly decreased their P4 secretion The results indicated that FSH can have a distinct cellular luteotropic effect during the early development luteal phase of the pig. FSH influenced P4 secretion by LCs whereas, with SCs it had no effect (10 and 10(2) ng) or P4 secretion decreased (10(3) ng).