A comparison of preparations of highly purified human pituitary luteinizing hormone: differences in the luteinizing hormone potencies as determined by in vivo bioassays, in vitro bioassay and immunoassay

Abstract

The LH [luteinizing hormone] potencies of 12 preparations of highly purified human pituitary LH from 6 laboratories, were estimated by 2 in vivo bioassays and an in vitro bioassay in terms of the International Reference Preparation of Human Pituitary Gonadotropins (FSH and LH) for Bioassay (coded 69/104); and by immunoassay in terms of the International Reference Preparation of Human Pituitary Luteinizing Hormone for Immunoassay (IRP; coded 68/40). The LH potencies varied between preparations, including the IRP (68/40), from 864 to 5740 IU/mg by seminal vesicle wt gain (SVW) assay; from 1510 to 11500 IU/mg by ovarian ascorbate depletion (OAAD) assay; from 4490 to 14500 IU/mg by in vitro (testicular interstitial-cell testosterone production) bioassay; and from 2030 to 9180 IU/mg by immunoassay. Estimates of protein content were based on the assumption that the absorbance of LH at 280 nm .**GRAPHIC**. was 6.0.