Role of glial cells, growth factors and steroid hormones in the control of LHRH-secreting neurons.
The mechanisms through which steroid hormones influence the LHRH system are not completely clarified and still represent a crucial and debated field of research in the neuroendocrine control of reproduction. Several data indicate that glial cells influence the activity of hypothalamic LHRH-secreting neurons, via the release of growth factors. It is now well known that glial cells express different kinds of steroid receptors and consequently may be considered as a target for the action of steroid hormones. To this purpose, the possibility that the effects of steroid hormones on LHRH neurons may be mediated by glial elements has been taken in consideration and observations supporting this hypothesis have been reported and discussed here. The results so far obtained strongly suggest that steroid hormones and growth factors, in order to exert their modulatory actions on LHRH dynamic, act in an integrated manner at the level of hypothalamic astrocytes.
Galbiati
M
M
Department of Endocrinology and Center of Excellence on Neurodegenerative Diseases, University of Milan, Via Balzaretti 9, 20133, Milan, Italy.
Martini
L
L
Melcangi
R C
RC
D000818:Animals; D004967:Estrogens / Q000502:physiology; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D006133:Growth Substances / Q000502:physiology*; D006728:Hormones / Q000494:pharmacology / Q000502:physiology*; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011374:Progesterone / Q000502:physiology; D013739:Testosterone / Q000502:physiology
D004967:Estrogens; D006133:Growth Substances; D006728:Hormones; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D011374:Progesterone