Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1992: ¥1,200,000 (Direct Cost: ¥1,200,000)
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Research Abstract |
A family of homologous, low-molecular-weight cytosolic proteins with high affinity for fatty acidsis expressed in mammalian tissues and called fatty acid-binding protein (FABP). Rat small intestine is knownto express several distinct FABPs, including newly-discovered intestinal 15 kDa protein (1-15P). We studied the expresion and localization of I-15P in the entire rat body, using the immunocytochemistry to localize protein and in situ hybridization to localize mRNA.Both techniques demonstrated the expression of I-15P in the enterocytes of ileum, luteal cells of ovary and a subpopulation of steroid-endocrine cells of adrenal gland. Immuno-electron microscopy further demonstrated that I-15P is localized in both the cytoplasmic and nuclear matrix regions of above cells. These results suggested the roles of I-15P not only in the transport of bile salts by ileal epithelium but also in the metabolisms of certain steroid hormones. Next, the immuohistohemical localizations of two types of FABPs, i.e., I-15P and heart FABP (H-FABP), were examined in the developing rat overies and in the rat overies induced to ovulate by gonadotropins. In the postnatal development of ovary, I-15P-immunoreactivity was localized temporarilyin a small subpopulation of theca/interstitial cells from 2 weeks to 4 weeks and then in the luteal cells from 5 weeks, in coincidence with the onset of cycles, into adulthood. In the immature (3 week old) ovaries inducedto ovulate by treatment with pregnant mare serum gonadotropin and human chorionic gonadotropin, I-15P-immunoreactivity first appeard in the luteinizing granulosa cells of large preovulatory follicles. In contrast, H-FABP-immunoreactivity was present temporarily in the follicular epithelial (granulosa) cells during the initial 2 weeks and thereafter in the theca/interstitial cells from 2 weeks postpartum into adulthood. These results suggested that two types of FABPs are expressed in distinct steroid cell populations of rat ovary, implecatin
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