Heterogeneity of follicle stimulating hormone: control and physiological function

Abstract

The existence of a heterogeneous population of follicle stimulating hormone (FSH) was described many years ago. Other pituitary glycoproteins, such as thyroid stimulating hormone (TSH) and luteinizing hormone (LH) as well as placental human chorionic gonadotrophin (HCG) also exhibit heterogeneity. Because FSH plays a significant role in a variety of ovarian activities such as follicular maturation, selection of the dominant follicle and ovulation, the possible role of sub-populations of FSH with distinct physicochemical characteristics is of great interest. After a great deal of investigation, the physiological significance of this biochemical phenomenon has yet to be fully understood. Investigators have employed immunoassays, in-vitro bioassays and radioreceptor assays to study the biological activity of the individual isoforms ofFSH. As more informations has accumulated, it has become clear that some ofthe initial assumptions used to interpret data may be incorrect. This review is Provided to Update the reader with availableinformation on the topic as it relates to FSH and to pointout issues that require re-evaluation in this area.