|Budget Amount *help
¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 2000 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1999 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1998 : ¥1,400,000 (Direct Cost : ¥1,400,000)
The effects of thyrotropin releasing hormone (TRH), adrenomedullin (AM ) , calcitonin-gene related peptide (CGRP), brain natriuretic peptide (BNP), parathyroid hormone (PTH), and bradykinin on isolated caecal circular smooth muscle cells from guinea pig were investigated. Our new findings are (1) that TRH inhibits the CCK-induced contraction via vasoactive intestinal peptide (VIP)-specific receptor, to which both VIP and atrial natriuretic peptide (ANP) binds, (2) the presence of interaction between AM and CGRP at the receptor level, (3) that BNP causes relaxation via not only VIP-specific receptor to which ANP also binds but also another receptor coupled with adenylate cyclase to which ANP does not bind, (4) that PTH induces relaxation via PTH receptor coupled with adenylate cyvlase, (5) the presence of one-way inhibitory receptor-receptor interaction from PTH receptor to VIP-preferring receptor and another one-way inhibitory receptor-receptor interaction from VIP-specific receptor to PTH receptor, and (6) that BK causes caecal circular smooth muscle contraction via unknown bradykinin receptor subtype.