Study on penile corpus cavernosum relaxation induced by Berberis amurensis Rupr (1075.10)

Abstract

Study on Penile corpus cavernosum relaxationinduced by Berberis amurensis RuprRui Tan 1, 2, , Hye Yoom Kim 1,2, Kyung Woo Cho2, Dae Gill Kang 1,2, and Ho Sub Lee 1,2*1College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570‐749, Republic of Korea; 2Hanbang Body‐fluid Research Center, Wonkwang University, Shinyong‐dong, Iksan, Jeonbuk, 570‐749, Republic of KoreaThe aim of the present study is to investigate whether a methanol extract of Berberis amurensis Rupr (BAR) augments penile erection. Preconstracted with phenylephrine (PE) in isolated endothelium‐intact rabbit corpus cavernosum, BAR relaxed penile smooth muscle in a dose‐dependent manner, which was inhibited by pretreatment with NG‐nitro‐L‐arginine methyl ester (L‐NAME), a nitric oxide synthase inhibitor, and 1H‐[1,2,4]‐oxadiazole‐[4,3‐α]‐quinoxalin‐1‐one (ODQ), a soluble guanylyl cyclase (sGC) inhibitor. BAR‐induced relaxation was significantly attenuated by pretreatment with tetraethylammonium (TEA), a nonselective K+ channel blocker for BKCa, IKCa and SKCa, and charybdotoxin, iberiotoxin, apamin, a selective Ca2+ sensitive K+ channel inhibitor, respectively. BAR increased cGMP levels of the corpus cavernosum in a concentration‐dependent manner. In addition, BAR caused increase of peak intracavernous pressure (ICP), ICP/MAP ratio and area under the carve (AUC) in a dose dependent manner in SD rats. Taken together, these results suggest that BAR augments penile erection via NO/cGMP system and Ca2+ sensitive‐K+ Channel in corpus cavernosum.