RECOMBINANT PORCINE FOLLICLE-STIMULATING-HORMONE PRODUCED IN BACULOVIRUS-INSECT CELLS INDUCES RAT OVULATION IN-VIVO AND GENE-EXPRESSION OF TISSUE-PLASMINOGEN ACTIVATOR IN-VITRO

Superovulatory responses in cattle are known to be highly variable. In the present study, a recombinant porcine follicle stimulating hormone (rpFSH) produced in baculovirus-insect cells was utilised to evaluate the role of this recombinant FSH in control of the ovulatory process. Immature hypophysectomised rats were implanted with oestrogen pellet (10 mg diethylstilbestrol) and then primed with pregnant mare serum go nadotropin (PMSG, 17.5 IU, sc). Fifty-two hours later, 100 mu g rpFSH or saline was injected (sc) to induce ovulation. All rats that receive d rpFSH ovulated with about eight ova rat(-1). whereas none of the con trol animals did. Ovulation induced by rpFSH was associated with an in crease in the ovarian activity and message levels of tissue-type plasm inogen activator (tPA), a protease important in the preovulatory degra dation of the follicle wall. Furthermore, addition of rpFSH to the cul tured rat granulosa cells resulted in a significant increase in tPA en zyme activity. These results demonstrate that rpFSH produced in baculo virus-insect cells has biological potency in ovulation as well as gene expression of tPA, providing a large advantage of this massive expres sion system in the reproduction of domestic animals.