5-Hydroxytryptamine Receptors, Especially the 5-HT4 Receptor, in Guinea Pig Urinary Bladder

The Japanese Journal of Pharmacology

Yasuko S.-Yamashita²  Muneshige Kaibara²  Akira Yoshida¹  Nobuyuki Tanaka¹  Kohtaro Taniyama² 

[1] Department of Rehabilitation and Physical Medicine, Faculty of Medicine, Kagoshima University;Department of Pharmacology, Nagasaki University School of Medicine

关键词: 5-HT receptor;    Guinea pig urinary bladder;    Receptor autoradiography;    Acetylcholine release;   

DOI  :  10.1254/jjp.89.349

学科分类：药理学

来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society

【 摘 要 】

References(23)Cited-By(7)The function of 5-hydroxytryptamine (5-HT) receptors, especially the 5-HT4 receptor, in the urinary bladder were examined in preparations isolated from the guinea pig by in vitro receptor autoradiography and determinations of mechanical activity and acetylcholine (ACh) release. Specific [125I]SB207710 binding sites were detected evenly throughout the urinary bladder. 5-HT (3 × 10−8 – 10−4 M) caused contractions of strips of the urinary bladder, in a concentration dependent manner. Ketanserin antagonized the 5-HT-induced contractions, while granisetron and SB204070 antagonized the contractions induced by high concentrations of 5-HT. Atropine inhibited the contractions induced by high concentrations of 5-HT. Ketanserin prevented the 5-HT-induced contractions in the presence of atropine, but granisetron and SB204070 did not affect the contractions under such a condition. 5-HT enhanced the electrically-stimulated (5 Hz, 0.5 ms) outflow of [3H]acetylcholine from strips preloaded with [3H]choline, and the enhancement was antagonized by granisetron and SB204070. Thus, the contractile response to 5-HT was mediated by activations of 5-HT2, 5-HT3 and 5-HT4 receptors. The 5-HT2 receptor may be a property of high affinity to 5-HT and located on the smooth muscle cells. The 5-HT4 as well as 5-HT3 receptor may be a property of low affinity to 5-HT and located on the cholinergic neurons.

【 授权许可】

Unknown