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 (P-4) content was determinated after 24 hrs of incubation. In nonstimulated conditions the basal P-4 production of large cells (LC(s)) was 65 fold higher than that of small cells (SCs) . The LC, 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 P-4 production by S Cs but higher doses (10(3) ng) significantly decreased their P-4 Secre tion. The results indicated that FSH can have a distinct cellular lute otropic effect during the early development luteal phase of the pig. F SH influenced P-4 secretion by LC(s) whereas, with SCs it had no effec t (10 and 10(2) ng) or P-4 secretion decreased (10(3) ng).