ROLE OF PROGESTERONE IN LUTEINIZING HORMONE-INDUCED FIBRONECTIN PRODUCTION AND DEPOSITION BY CHICKEN GRANULOSA-CELLS IN-VITRO

The role of progesterone in luteinizing hormone- (LH) induced fibronec tin production and deposition by chicken ovarian granulosa cells was e xamined in vitro. Granulosa cells isolated from pre-ovulatory follicle s of the domestic hen ovary were incubated in serum-free Medium 199, a nd the total amount of fibronectin (deposited, secreted into the mediu m and associated with cells) produced was measured by ELISA, LH increa sed the amount of fibronectin deposited by granulosa cells, Similarly, it increased the quantity of fibronectin secreted into the medium or associated with cells, Cyanoketone (an inhibitor of progesterone synth esis) suppressed dose dependently basal and LH-induced fibronectin dep osition, Cyanketone also attenuated the total amount of fibronectin pr oduced by control or LH-stimulated granulosa cells. Exogenous progeste rone reversed the inhibitory effects of cyanoketone on basal and LH-in duced fibronectin production and deposition. The non-degradable synthe tic progestin R5020 stimulated fibronectin production in a dose-depend ent manner, R5020 also reversed the inhibitory effects of cyanoketone on LH-induced fibronectin production and deposition, The antiprogestin , ZK 98.299, inhibited basal and LH-stimulated fibronectin production, The data demonstrate that endogenous progesterone regulates fibronect in production and deposition perhaps in an intracrine/autocrine manner , They indicate that LH-stimulated fibronectin production and depositi on by chicken granulosa cells is mediated (at least in part) by proges terone.