RESUMEN
ObjectiveTo investigate the genomic and non-genomic effects of 17β-estradiol on gallbladder smooth muscle strips of guinea pig and their possible mechanism. MethodsAfter ovariectomized operation (OVX) and subcutaneous injection of 17β-estradiol, the contents of serum estradiol and cholecystokinin-octopeptide (CCK-8) of the sham operation group (Sham) guinea pigs, the OVX group, the OVX and subcutaneous injection 17β-estradiol for 1 day (OVX+E2, 1 d), 3 days (OVX+E2, 3 d) and 7 days (OVX+E2, 7 d) were detected by EILSA respectively. The effects of CCK-8/Ach on constriction of gallbladder muscle strip were observed among various groups by using tension transducer, and the acute effects of 17β-estradiol on guinea pig gallbladder smooth muscle strips were observed to probe its possible mechanism. ResultsCompared with the Sham group, the serum contents of estradiol and CCK-8 decreased in OVX group (P＜ 0. 05) whereas the sensitivity of OVX guinea pigs gallbladder muscle strips to CCK-8/Ach increased (P＜0.05). With the extension of the subcutaneous injection 17β-estradiol time (for 1, 3, 7 days), both the serum estradiol and CCK level increased (P＜ 0.05) while the guinea pig gallbladder strips sensitivity to CCK-8/Ach decreased (P＜0.05).17β-estradiol at concentration ranging from 10 9 to 10-7 mol/L have no effect on the guinea pig gallbladder strips contraction (P＞0.05), but at concentration of 10-6 and 10 5 mol/L, it can inhibit the gallbladder contraction (P＜0.05). The blocking agents, such as nimodipine, atropine, devazepide, ICI 182,780 and Y-27632, can block the inhibited effects of 17β-estradiol. ConclusionThe 17β-estradiol can affect the gallbladder motility, both by genomic and non-genomic pathway.