Effects of tetrandrine on cytosolic free calcium concentration in corpus cavernosum smooth muscle cells of rabbits.
- Author:
Ji-Hong LIU
1
;
Jun CHEN
;
Tao WANG
;
Bo LIU
;
Jun YANG
;
Xiao-Wen CHEN
;
Shao-Gang WANG
;
Chun-Ping YIN
;
Zhang-Qun YE
Author Information
- Publication Type:Journal Article
- MeSH: Alkaloids; pharmacology; Animals; Benzylisoquinolines; pharmacology; Calcium; metabolism; Cytosol; drug effects; metabolism; Male; Muscle Relaxation; Muscle, Smooth, Vascular; cytology; metabolism; Penis; cytology; metabolism; Phenylephrine; pharmacology; Potassium Chloride; pharmacology; Rabbits
- From: Asian Journal of Andrology 2006;8(4):405-409
- CountryChina
- Language:English
-
Abstract:
AIMTo study the relaxation mechanisms of tetrandrine (Tet) on the corpus cavernosum smooth muscle.
METHODSThe corpus cavernosum smooth muscle cells from New Zealand white rabbits were cultured in vitro. [Ca(2+)](i) was measured by Fluorescence Ion Digital Imaging System, using Fluo-2/AM as a Ca(2+)-sensitive fluorescent indicator.
RESULTSTet (1, 10 and 100 micromol/L) had no effect on the resting [Ca(2+)](i) (P>0.05). In the presence of extracellular Ca(2+) (2.5 mmol/L), Tet (1, 10 and 100 micromol/L) inhibited [Ca(2+)](i) elevation induced by high K(+) and phenylephrine (PE) in a concentration-dependent manner (P>0.05). In calcium free solution containing egtaic acid, Tet (1 and 10 micromol/L) had no inhibitory effects on [Ca(2+)](i) elevation induced by PE (P>0.05). However, Tet (100 micromol/L) inhibited [Ca(2+)](i) elevation induced by PE (P>0.05).
CONCLUSIONTet inhibited the Ca(2+) influx from the extracellular site via voltage-activated Ca(2+) channel and alpha(2)-adrenoceptor-operated Ca(2+) channel. At a high concentration, Tet might inhibit the cytosolic calcium pool release in cultured corpus cavernosum smooth muscle cells. This inhibitory action on [Ca(2+)](i) might be one of the relaxation mechanisms of Tet on the corpus cavernosum smooth muscle.
