Receptorial and Functional Overlapping between Thyrotropin (TSH) and Gonadotropins (FSH, LH): Phylogenetic, Ontogenetic and Clinical Application Aspects

Abstract

There are overlapping in the receptorial hormone binding, as well as the physiological and pathological functions of glycoprotein hormones from the unicellular level (Tetrahymena) to mammals (human beings). The overlapping can be explained by the analogous structure of receptors and similarities of hormones; however, the specificity-in contrast, to the hormonal similarities-is not understandable. The overlap is more expressed during the ontogenetic development however; it is present in matured (adult) age, sometimes causing characteristic alterations and diseases in humans. Overlapped (nonspecific) hormones' effect can be stronger, than that of the original (specific) ones. In the fetal, perinatal and early postnatal development the overlapping could cause faulty hormonal imprinting with late consequences in sexual or thyroid regulated functions. Imprinting can be executed also in tissue cultures with similar consequences. Overlapping in adults are manifested in alteration of sexuality (menstrual disturbances and infertility included) and bone loss (osteoporosis) as well, like other diseases.