Expression and localization of leptin receptor in the normal rat pituitary gland.
Leptin receptor (leptin-R) is a polypeptide consisting of a single transmembrane-spanning component. Recent studies performed by reverse transcriptase polymerase chain reaction (RT-PCR) have shown the production of leptin-R in various tissues including the pituitary, hypothalamus and reproductive organs. The localization of leptin-R protein in the pituitary gland, however, has not been extensively studied. This study deals with the expression of leptin-R in the normal rat pituitary gland, which was disclosed primarily in the plasma membrane fraction by immunoblotting and immunohistochemical staining methods. Double immunohistochemical staining revealed that the colocalization of leptin-R and anterior pituitary hormone expression was seen mainly in growth hormone (GH)-secreting cells (97.4 +/- 1.3%; GH-positive cells/leptin-R-positive cells), but in less than 1% of prolactin (PRL)-, adrenocorticotropic hormone (ACTH)-, thyroid-stimulating hormone-beta (TSH beta)- and follicle-stimulating hormone-beta (FSH beta)/luteinizing hormone-beta (LH beta)-positive cells. In contrast, leptin was localized most frequently in FSH beta/LH beta- and less frequently in TSH beta-positive cells. The above findings suggest that, in the rat anterior pituitary gland, there are paracrine relationships between leptin-producing cells and cells with leptin-R, which may regulate the function of GH cells.
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Department of Pathology, Tokai University School of Medicine, Bohseidai, Isehara, Kanagawa, 259-1193, Japan.
Nagata
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Takekoshi
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Osamura
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RY
D000324:Adrenocorticotropic Hormone / Q000032:analysis; D000818:Animals; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis; D037201:Follicle Stimulating Hormone, beta Subunit; D015870:Gene Expression; D013006:Growth Hormone / Q000032:analysis; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000032:analysis; D008297:Male; D010903:Pituitary Gland, Anterior / Q000737:chemistry* / Q000502:physiology*; D011388:Prolactin / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D020133:Reverse Transcriptase Polymerase Chain Reaction
D002352:Carrier Proteins; D037201:Follicle Stimulating Hormone, beta Subunit; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013006:Growth Hormone