Insulin-Like Growth Factor-I and Its Receptor in Mouse Pituitary Glands

概要

論文の詳細を見る
Insulin-like growth factor-I(IGF-I)is produced in the liver and other peripheral tissues in response to growth hormone(GH)stimuli. IGF-I regulates diverse physiologicai functions in an autocrine and/or paracrine manner. IGF-I and IGF-I receptor(type-I receptor)are expressed in human and rat pituitary glands. However, the cell types of IGF-I-expressing cells and target cells of IGF-I in the pituitary glands are not known. The present study was aimed to identify the cell types of IGF-I-expressing cells and of its type-I receptor-expressing cells in mouse pituitary glands. In the mouse pituitary glands, IGF-I mRNA and IGF-I receptor mRNA were detected by reverse transcription-polymerase chain reaction(RT-PCR). IGF-I-expressing cells and its receptor-expressing cells were detected by non-radioisotopic in situ hybridization using mouse IGF-I cDNA and IGF-I receptor cDNA probes, and their cell types were immunocytochemically determined using antibodies raised against pituitary hormones. We found that somatotrophs expressed both IGF-I and IGF-I receptors, and some of corticotrophs expressed IGF-I receptors. Co-localization of IGF-I and GH in the same cultured pituitary cells was observed by dual-labelling immunocytochemistry. The present study demonstrated that pituitary IGF-I produced in somatotrophs regulated functions of somatotrophs and corticotrophs in an autocrine and/or paracrine manner.
社団法人日本動物学会の論文