A New Sensitive Bio-ass ay for Follicle-Stimulating Hormone (FSH)

Abstract

A specific and very sensitive assay method for FSH using intact immature female mice was devised. This method is based on the synergism between FSH and a small amount of human chorionic gonadotrophin (HCG). The test material mixed together with 0.25 IU or 0.1 IU HCG is injected subcutaneously daily for 3 days into intact immature female mice. On the fourth day, necropsy is performed and uterine weight is measured after evacuation of any fluid. Using NIH-FSH and IRP-HMG, linear log-dose response curves were obtained. By contrast, the ovine NIH-LH standard evoked no significant response when administered in doses up to 200 μg. Contamination of FSH with over 10 μg NIH-LH sometimes reduced the uterine response caused by FSH; however, contamination with less than 6 μg NIH-LH did not interfere with the response. Other anterior and posterior hypophysial hormones did not give any significant response when administered with HCG. The minimal effective dose of NIH-FSH-S-1 ovine standard and International Reference Preparation for Human Menopausal Gonadotrophin was 2 and 10 μg, respectively. (Endocrinology74: 440, 1964)