Estrogen modulates norepinephrine-induced accumulation of adenosine cyclicmonophosphate in a subpopulation of immortalized luteinizing hormone-releasing hormone secreting neurons from the mouse hypothalamus

A subpopulation of luteinizing hormone-releasing hormone (LHRH)-producing c ells that express the intermediate filament protein vimentin and the neuron al marker neurofilament 145, but not neurofilament 200 nor glial fibrillary acidic protein, has been isolated from GT1-7 cultures. These cells express the mRNA encoding estrogen receptor alpha (ER alpha) and respond to physio logical concentrations of 17 beta -estradiol (E-2) by reducing the accumula tion of cyclic adenosine monophosphate induced by norepinephrine, but not t hat induced by direct activation of adenylate cyclase. These results indica te that the activity of LHRH-producing neurons may be directly modulated by estrogen. In addition, they are suggestive of an estrogen-dependent desens itization of the beta -adrenoceptor in these cells. (C) 2001 Published by E lsevier Science Ireland Ltd.