ABSTRACT
AIM: To observed the effects of BWYJ (a naftopidil ramification) on intracellularlar free Ca~(2+)([Ca~(2+)]_i) in smooth cells (SMCs) in order to further explore its vasodilative mechanisms. METHODS: The [Ca~(2+)]_i was determined with the Fura-2/AM loaded SMCs in aorta of rabbit, and the effects of BWYJ on the elevation induced by NA, and high potassium and 5-HT were observe. RESULTS: In the Fura-2/AM loaded SMCs, BWYJ had no effect on the resting [Ca~(2+)]_i, but it reduced the increase of [Ca~(2+)]_i induced by NA and 5-HT, and there was no influence on the increase of [Ca~(2+)]_i induced by high potassium. CONCLUSION: The vasodilative mechanisms of BWYJ may be related to its inhibitive effects on the Ca~(2+)-influx and Ca~(2+)-release mediated by ?_1- and 5-HT_(2A) receptors. It inhibits the release of intracellular calcium, and the result is it decrease the [Ca~(2+)]_i in SMCs.