IN-VITRO BIOPOTENCY AND GLYCOFORM DISTRIBUTION OF RECOMBINANT HUMAN FOLLICLE-STIMULATING-HORMONE (ORG-32489), METRODIN AND METRODIN-HP

In this study the in-vitro biopotency and glycoform distribution of hu man recombinant follicle stimulating hormone (FSH, Org 32489) has been assessed. The biopotency of recombinant FSH was studied using animal (rat Sertoli) and human (granulosa-lutein) cell models. Recombinant FS H, as measured in the rat Sertoli cell assay, was more potent than the urinary preparations Metrodin, Metrodin-HP and IS 70/45 with half max imal stimulation (ED(50); mean +/- SEM, n > 3) occurring at 2.2 +/- 0. 5 IU/I (recombinant FSH), 4.7 +/- 1.1 IU/I (Metrodin), 13.2 +/- 0.7 IU /I (Metrodin-HP) and 6.4 +/- 0.3 IU/I (IS 70/45); the pituitary prepar ation IRP 83/575 had an ED(50) of 10.4 +/- 0.1 IU/I. Using human granu losa-lutein cells, cultured for up to 4 days in the absence of exogeno us steroid precursors, recombinant FSH was either without effect (thre e out of five patients) or inhibited both oestradiol and progesterone secretion. FSH (83/575) was without effect on oestradiol with preparat ions from any of the patients but slightly stimulated (134 +/- 8%; mea n +/- SEM, P < 0.05) progesterone production at the highest dose (80 I U/I). The distribution of FSH isoforms, assessed by polyclonal radioim munoassay, following chromatofocusing over the ranges pH < 3.5 and pH 3.5-7.0 respectively was recombinant FSH, 12.4 and 87.6%; Metrodin, 19 .8 and 80.2%; Metrodin-HP, 50.2 and 49.8%; IS 70/45, 15.0 and 85.0%; I S 83/575, 70.9 and 29.1%. All glycoforms were pi <7.0 for the five pre parations. In conclusion: (i) the potency of FSH as measured in the ra t Sertoli cell assay increases in the order Metrodin-HP < pituitary IR P 83/575 much less than Metrodin < IS 70/45 < recombinant FSH; (ii) in contrast to 83/575, recombinant FSH inhibits steroidogenesis in human granulosa-lutein cells isolated from some patients; (iii) the glycofo rm distribution of recombinant FSH resembles Metrodin more closely tha n Metrodin-HP which is far more acidic in nature.