EFFECTS OF IMMUNIZATION AGAINST GONADOTROPHINS ON MALE REPRODUCTIVE FUNCTIONS

This chapter discusses the effects of immunization against gonadotrophins on male reproductive functions. It also discusses the neutralization of the gonadotrophins luteinizing hormone (LH) and follicle stimulating hormone (FSH) in male animals, the effects of removing these hormones on testicular steroidogenesis and spermatogenesis, on centrally-occurring events and on sexual characteristics. As immunization—whether active or passive—can be performed at any stage of the life span of the animal, the role of the gonadotrophins in the development of reproductive function can be elucidated in neonatal, immature, and mature animals. This technique has the distinct advantage over surgical removal of the pituitary that the hormone under consideration is neutralized specifically, and all other pituitary functions are left intact. It is not possible in certain cases to obtain homologous pituitary preparations to perform replacement studies in hypophysectomized animals, especially in nonhuman primates. However, the biological effects following immunization do depend on the individual antibody characteristics, such as hormone specificity, neutralizing capacity, affinity and species cross-reactivity, the latter being especially important when performing studies with heterologous antibodies or antigens.