Ionic mechanism underlying chance of L-type Ca~(2+) current in isolated rat ventricular myocytes induced by hypercholesterolemia / 中国药理学通报

ABSTRACT

Aim To investigate the effect of hypercholesterolemia on L-type Ca2+(ICa-L) current and intracellular calcium concentration ([Ca2+]i) in single ventricular myocytes of hypercholesterolemic rats.Methods 12 male wistar rats were randomly divided into two dietary groupsa group fed a normal diet(n=6)and a group fed high-cholesterol diet(n=6) for 4 weeks,respectively. The level of serum lipid was examined.Zymolytic method was used to isolate single ventricular myocytes from hypercholesterolemic and normal rats,which were loaded with Ca2+-sensitive fluorescent 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.Results There was no significant influence exhibited on TG level.However, the serum total cholesterol(TC)level of hypercholesterolemic rats was much higher than that of model control group; at the test potential of 0 mV, ICa-L decreased from(-8.56?1.29)pA/pF(Control)to(-5.24?0.90) pA/pF(HC)(n=6 in each group,P