TY - JOUR
T1 - Gonadotropin-releasing hormone receptor gene expression in rat anterior pituitary
AU - Mertani, Hichem C.
AU - Testart, Catherine
AU - Ouhtit, Allal
AU - Brisson, Christine
AU - Morel, Gérard
PY - 1996/4
Y1 - 1996/4
N2 - Gonadotropin-releasing hormone (GnRH) effects on the lactotroph function have been widely studied, but they probably result from paracrine interactions. No visual data about GnRH receptor in the pituitary are available. In order to identify the GnRH target cells in the pituitary of adult rats, the cellular distribution of rat GnRH receptor mRNA was investigated by electron microscopy, using in situ hybridization on ultrathin pituitary frozen sections. In situ hybridization was performed using a digoxigenin-labeled ol igonucleotide probe revealed by an indirect immunogold reaction. Gonadotropin-releasing hormone receptor mRNA was found in the cytoplasmic matrix, apposed to the endoplasmic reticulum and the nucleus of the gonadotrophs, which were identified by their ultrastructural characteristics, and by the presence of luteinizing hormone (LH) immunoreactivity. It was also found in the lactotrophs, which were revealed by the immunocytological detection of prolactin. No GnRH receptor mRNA was detected in corticotrophs, somatotrophs, thyrotrophs or hepatocytes. This result, without excluding paracrine effects, clearly showed that in addition to the gonadotrophs, the lactototrophs are likely to be direct target cells for the hypothalamic GnRH.
AB - Gonadotropin-releasing hormone (GnRH) effects on the lactotroph function have been widely studied, but they probably result from paracrine interactions. No visual data about GnRH receptor in the pituitary are available. In order to identify the GnRH target cells in the pituitary of adult rats, the cellular distribution of rat GnRH receptor mRNA was investigated by electron microscopy, using in situ hybridization on ultrathin pituitary frozen sections. In situ hybridization was performed using a digoxigenin-labeled ol igonucleotide probe revealed by an indirect immunogold reaction. Gonadotropin-releasing hormone receptor mRNA was found in the cytoplasmic matrix, apposed to the endoplasmic reticulum and the nucleus of the gonadotrophs, which were identified by their ultrastructural characteristics, and by the presence of luteinizing hormone (LH) immunoreactivity. It was also found in the lactotrophs, which were revealed by the immunocytological detection of prolactin. No GnRH receptor mRNA was detected in corticotrophs, somatotrophs, thyrotrophs or hepatocytes. This result, without excluding paracrine effects, clearly showed that in addition to the gonadotrophs, the lactototrophs are likely to be direct target cells for the hypothalamic GnRH.
KW - Electron microscopy
KW - Gonadotropin-releasing hormone receptor
KW - Immunocytology
KW - In situ hybridization
KW - Paracrine
KW - Rat anterior pituitary
KW - mRNA
UR - http://www.scopus.com/inward/record.url?scp=0029785973&partnerID=8YFLogxK
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U2 - 10.1007/bf02782760
DO - 10.1007/bf02782760
M3 - Article
AN - SCOPUS:0029785973
SN - 1355-008X
VL - 4
SP - 159
EP - 163
JO - Endocrine
JF - Endocrine
IS - 2
ER -