Effects of emodin on the intracellular calcium concentration (Ca2+i) and L-type calcium current of the single ventricular mytocytes from guinea pig.
- Author:
Ying LIU
1
;
Hong-li SHAN
;
Hong-li SUN
;
Shu-zhuang HE
;
Bao-feng YANG
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Calcium; metabolism; Calcium Channels, L-Type; drug effects; Cell Separation; Dose-Response Relationship, Drug; Emodin; administration & dosage; pharmacology; Female; Guinea Pigs; Heart Ventricles; Male; Myocytes, Cardiac; cytology; metabolism
- From: Acta Pharmaceutica Sinica 2004;39(1):5-8
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo study the effects of emodin on intracellular calcium concentration ([Ca2+]i) and L-type calcium current of the single ventricular myocytes from guinea pig.
METHODSEnzymatic dissociation was used to isolate single ventricular myocytes from adult guinea pig. They were loaded with Ca2(+)-sensitive fluorecent indicator Fluo-3/AM. [Ca2+]i represented by fluorescent intensity (FI) was measured by laser scanning confocal microscope. Whole cell patch clamp technique was used to record ICa-L.
RESULTSAt resting status, [Ca2+]i was not affected by emodin (1-100 mumol.L-1). Emodin at the concentration of 1 mumol.L-1 was shown to increase the [Ca2+]i induced by 60 mmol.L-1 KCl. The peak value of fluorescent intensity was increased from 1,877 +/- 551 to 2,905 +/- 739 (n = 8, P < 0.05). Emodin at the concentration of 10 mumol.L-1 had no effect on the increase of [Ca2+]i induced by 60 mmol.L-1 KCl. However, the increase of [Ca2+]i induced by KCl was reduced to 1,214 +/- 335 (n = 8, P < 0.05) by 100 mumol.L-1 emodin. The density of ICa-L was increased from (-6.2 +/- 1.3) pA/pF to (-8.3 +/- 0.3) pA/pF (n = 6, P < 0.05) by 1 mumol.L-1 emodin at the test pulse of 0 mV. The current was not altered by 10 mumol.L-1 emodin. But it was inhibited from (-6.6 +/- 1.0) pA/pF to (-3.80 +/- 0.16) pA/pF (n = 6, P < 0.05) by 100 mumol.L-1 emodin at the test pulse of +10 mV.
CONCLUSIONEmodin has two-way regulation on [Ca2+]i and ICa-L of cardiomyocytes in guinea pig.
