EFFECTS OF HUMAN MENOPAUSAL GONADOTROPHIN PREPARATIONS IN DIFFERENT BIOASSAY METHODS

Abstract

Several gonadotropin preparations, HMG (Human Menopausal Gonadotropin), HPG (Human Pituitary Gonadotropin) and NIH FSH S1 (a FSH preparation distributed by the National Institute of Health) were investigated for biological activity, using 3 methods of assay. The rat augmentation test, specific for FSH, and the rat seminal vesicle weight test, specific for ICSH both gave statistically valid results. The potencies were expressed in terms of the IRP (International Reference Preparation for HMG), and the International HCG Standard respectively. The gonadotropic activity as determined by the rat uterine weight method was expressed in terms of IRP and in terms of the International HCG Standard. Good agreement was found between the results in the uterine weight method and the seminal vesicle test, suggesting a strong ICSH dependence for the former. On the other hand, the results of the uterine weight method and the augmentation test were not in agreement. Consequently the rat uterine weight method must be regarded as completely unsuitable for the assay of FSH-activity. Among the 3 test methods studied, the augmentation test appears to be the only 1 suitable for the assay of the FSH content of gonadotropin preparations for clinical use. Fractionation of HMG with ethanol led to preparations with high FSH activity, 200 to 300 times that of IRP, but with little ICSH activity. Most of the ICSH was concentrated in other fractions, indicating that both hormones can be separated. In starch gel electrophoresis these fractions showed different patterns.