BACULOVIRUS-INSECT CELL PRODUCTION OF BIOACTIVE PORCINE FSH

The in vitro and in vivo bioactivity of recombinant porcine FSH (rpFSH ) produced from insect cells through use of a baculovirus expression s ystem were studied and compared with those of natural FSH preparations . Determination of in vitro bioactivity, using the rat Sertoli cell ar omatase bioassay, indicated that rpFSH is as active as purified pituit ary FSH. Determination of in vivo bioactivity, using the mouse uterine weight bioassay, indicated that rpFSH is as active as purified pituit ary FSH. Using the mouse Leydig cell testosterone bioassay, it was dem onstrated that the intrinsic LH bioactivity of rpFSH is negligible. Th e increases in ovarian and uterine weight, and the stimulation in foll icular growth in immature hypophysectomized rats induced by rpFSH supp lemented with hCG were comparable to those induced by natural FSH prep arations. Furthermore, rpFSH alone in hypophysectomized mice stimulate d preantral follicular growth to preovulatory stages, and the subseque nt injection of hCG caused ovulation. These results demonstrate that i n vitro and in vivo biological characteristics of rpFSH produced from baculovirus-insect cells are indistinguishable from those of FSH isola ted from natural sources. (C) 1997 by Elsevier Science Inc.