Gonadotropin-Releasing Hormone and Organs of the Immune System

In this review, we address the physiological aspects of thegonadotropin-releasing hormone (GnRH) effects on the immune organs,such as red bone marrow, thymus, spleen, and lymph nodes. The useof GnRH drugs leads to the replacement of red bone marrow with yellowone and an increase in the content of lymphoid and myeloid progenitorcells. These processes are paralleled by osteoporosis due to increasedbone resorption with changes in calcium metabolism and a decreasein the density of various bone tissues, although there are opposingreports that GnRH has no effect on bone density and calcium metabolism.GnRH affects the thymus during both embryonic development and postnatalontogenesis, in inflammation and age-related involution. Not onlydoes GnRH cause changes in the thymus, but the thymus may in turninfluence the GnRH system. Although a direct impact of GnRH on spleniccells has not been detected, splenic mass changed due to activeimmunization against GnRH in experiment. Unfortunately, very fewarticles demonstrate the physiological mechanisms of immunomodulationin such conditions. In any case, the obvious insufficiency and inconsistencyof publications on each aspect of GnRH effects indicate that theyare still poorly understood, and it is worth furthering not onlyapplied but also fundamental studies in this direction, particularlyin the context of developing effective systems for immune control.