Jpn. J. Pharmacol. 83 (1), 86-88 (2000)


Effects of Zaldaride Maleate, an Antidiarrheal Compound, on Intracellular Ca2+-Mediated Short-Circuit Current Response in the Rat Colonic Mucosa

Nobuo Aikawa, Akira Karasawa and Kenji Ohmori


The Drug Development Research Laboratories, Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co., Ltd.,
1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8731, Japan

Abstract: The effect of zaldaride maleate (ZAL) on intracellular Ca2+-mediated short-curcuit current (Isc) response in rat colonic mucosa was investigated. The Isc response to acetylcholine was partially reduced by the neuronal blocker tetrodotoxin. The tetrodotoxin-sensitive Isc response to acetylcholine was inhibited by ZAL. The tetrodotoxin-insensitive effect, which indicates direct stimulation of acetylcholine in colonic mucosa, was not affected by ZAL. The Isc response to the Ca2+ ionophore A23187 was reduced by ZAL in the presence of tetrodotoxin. These results suggest that ZAL reduces colonic ion secretion by inhibiting a tetrodotoxin-sensitive neuronal pathway and an intracellular Ca2+ pathway in epithelium.

Keywords: Zaldaride maleate, Calmodulin, Short-circuit current (Isc)


Copyrightę The Japanese Pharmacological Society 2000

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