3-B-P-041 〇海野 年弘^1,2、Pimpjong Kiattisak²、水谷 太一¹、小嶋 地咲¹、棚橋 靖之³、太田 利男⁴、松山 勇人¹ Toshihiro Unno^1,2, Kiattisak Pimpjong², Taichi Mizutani¹, Chisaki Kojima¹, Yasuyuki Tanahashi³, Toshio Ohta⁴, Hayato Matsuyama^{1 1}岐阜大・応用生物科学部・獣医薬理、²岐阜大・院共同獣医・基礎獣医、³京都産業大・生命科学部・先端生命科学科、⁴鳥取大・院共同獣医学・基礎獣医学 ¹Fac. Appl. Biol. Sci., Gifu Univ., ²Joint Grad. Sch. Vet. Sci, Gifu Univ., ³Fac. Life. Sci., kyoto Sangyo Univ., ⁴Joint Grad. Sch. Vet. Sci, Tottori Univ. In prostate gland, the genes of transient receptor potential melastatin 4 (TRPM4) channels are highly expressed. However, the role of TRPM4 channels in the contractile response in this organ has not yet been elucidated. Here, we examined if TRPM4 channels are involved in the adrenergic and cholinergic contractions in mouse prostate smooth muscle preparations. Contractile responses evoked by electrical field stimulation of intrinsic adrenergic or cholinergic nerves or exogenously applied noradrenaline (NA) or carbachol (CCh) were isometrically recorded and effects of the specific TRPM4 channel inhibitors, 9-phenanthrol and 4-chloro-2-(1-naphthyloxyacetamido) benzoic acid (NBA), on those contractile responses were investigated. 9-phenanthrol and NBA inhibited both adrenergic nerve-evoked and NA-induced contractions. Similar inhibitory effects of TRPM4 channel inhibitors were obtained in cholinergic contractions. 9-phenanthrol and NBA significantly inhibited noradrenaline-induced contractions in the abdominal aorta preparations. However, the inhibitory effects were much stronger in the prostate gland than in the arterial tissue. The present results suggest that TRPM4 channels are involved in adrenergic and cholinergic contractions in the mouse prostate gland. Thus, TRPM4 channels may be a new therapeutic target for treating benign prostatic hyperplasia without noticeable vasodilation.