[Effects of berberine on intracellular calcium concentration in smooth muscle cells of guinea pig colon].
The purpose of the present investigation is to study how berberine (Ber) affect the intracellular free calcium concentration ( Ca(2+) (i)) of the smooth muscle cells of guinea pig colon by means of biwavelength spectrophotometry with Fura 2 AM in a cell suspension specimen. In the resting state, Ca(2+) (i) in HEPES Ringer solution (CaCl2 1.5 mmol/L) was 108 9.4 nmol/L (n=7), which was not significantly affected by Ber. On the other hand, Ber inhibited the increased Ca(2+) (i) induced by 60 mmol/L KCl in a dose dependent manner, with a value of IC(50) being 34.09 micromol/L. 30, 100 micromol/L Ber also inhibited 10 micromol/L ACh evoked Ca(2+) (i) elevation in a dose dependent manner either in the presence or absence of extracellular Ca(2+). In addition, Ber inhibited cyclopiazonic acid (CPA) stimulated Ca(2+) (i) elevation dose dependently. This effect was more potent in HEPES Ringer solution (IC(50)=37.79 micromol/L) than in Ca(2+) free medium (IC(50)=49.70 micromol/L). The above results suggest that Ber exerts an inhibitory effect on the extracellular Ca(2+) influx and the Ca(2+) release from intracellular stores.
Cao
J W
JW
Digestive Disease Research Division, The First Affiliated Hospital of Hubei Medical University, Wuhan 430060, China. Luotang@public.wh.hb.cn
Luo
H S
HS
Yu
B P
BP
Sheng
Z X
ZX
Yu
J P
JP
D000818:Animals; D001599:Berberine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects; D002469:Cell Separation; D003106:Colon / Q000166:cytology / Q000378:metabolism; D005260:Female; D016257:Fura-2; D006168:Guinea Pigs; D007211:Indoles / Q000494:pharmacology; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D007211:Indoles; D001599:Berberine; D002118:Calcium; D016257:Fura-2; C000543:cyclopiazonic acid