| Budget Amount *help |
¥3,890,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥390,000)
Fiscal Year 2007: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2006: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Research Abstract |
Recently novel peptide neuromedin S (NMS) was identified from rat hypothalamus. We previously showed that icv injection of NMS caused cFos expression in PVN, SO and Arc nucleus in rats. Therefore, I investigated the role for neuromedin S in vasopressin release and urinary output. Icv injection of NMS resulted in decrease of nocturnal urinary output in dose dependent manner. In addition, icv injection of NMS increased plasma vasopressin levels. These results suggest that central NMS may exert a physiological antidiuretic action via vasopressin release.
In this study, the physiological role of the novel peptide, NMS, on feeding regulation was investigated. Intracerebroventricular (icv) injection of NMS decreased 12-h food intake during the dark period in rats. This anorexigenic effect was more potent and persistent than that observed with the same dose of NMU. Icv administration of NMS increased proopiomelanocortin (POMC) mRNA expression in the arcuate nucleus (Arc) and corticotropin releasing hormone (CRH) mRNA in the paraventricular nucleus (PVN). PAfter icv injection of NMS, Fos-immunoreactive cells were detected in both the PVN and Arc. When neuronal multiple unit activity was recorded in the PVN before and after icv injection of NMS, a significant increase in firing rate was observed 5 min after administration, and this increase continued for 100 min.
These results suggest that the novel peptide, NMS, may be a potent anorexigenic hormone in the hypothalamus, and that expression of POMC mRNA in the Arc and CRH mRNA in the PVN may be involved in NMS action on feeding.
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