ABSTRACT
Objective To study the level of serum lipids and body-fat content of high-fat diet induced pbesity rats(DIO).explore the relationship between intracellular caleium and ventrieufar arrhythmia.Methods Sixty male Sprague-Dawley(SD)rats were divided into control group(15)and experiment group(45),high-fat diet was administrated for 12 weeks to established obesity model,15 rats were selected into obesity group according to their body weight gain.The standard 2-lead electrocardiograph was used to detect the incidence and scores of arrhythmia induced by barium chloride(BaCl2,0.1 mg/kg)for 1 hour on every 8 rats from different groups respectively.Body-fat content.the level of serum total cholesterol(TC),triglyceride(TG),low density lipopmtein cholesterol (LDL-C) and high density lipopmtein cholesterol (HDL-C)were measured.The epididymal(EP),retroperitoneal (RE) and mesenteric(ME)white adipose pads was measured to obtain the body fat content.Single ventricular myrocytes of rats were isolated by enzymatic dissociation.The confocal laser scanning microscope was used to record basic intraceUular calcium level([Ca2+]i).Results The body-fat content in obesity group[(7.71±0.74)%] was significantly higher than control group[(4.69±0.37)%](t＝3.650,P＜0.05).The level of serum TC,TGand LDL-C were significantly higher(t＝3.801,2.778,3.536.P＜0.05) in obesity group[(1.26±0.04),(0.58±0.10),(0.51±0.04)mmol/L]than those in control group[(0.92±0.08),(0.29+0.03),(0.31±0.04) mmol/L].The level of serum HDL-C wa8 decreased gradually from control group[(0.53±0.05)mmol/L] toobesity group[(0.52±0.02)mmol/L],but there waft no significant difference between them(t＝0.186,P＞0.05).The incidence of arrhythmia induced by BaCl2(0.1 mg/kg)in obesity group was significantly higher than controlgroup(X2＝5.333,P＜0.05),and the scores of arrhythmla was increased in obesity group(2.5±0.6)too.The fluorescence intensity standing for[Ca2+]i was increased significantly(t＝2.409,P＜0.05)from obesity group(247.96±20.03)to control group (174.25±23.13).Conclusion As the free cytosolic calcium begin to accumulate,the arrhythmia morbidity is increased in obesity rats.
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 groups:a 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
ABSTRACT
Aim To investigate the effects of dihydromyricetin on the apoptosis in AGZY-83-a tumor cells and its relevant mechanisms.Methods The survival rate of AGZY-83-a cells was assayed by MTT dye reduction.The cellular apoptosis was analyzed by TUNEL method and caspase-3 activity.The intracellular free calcium i was detected to explore the apoptotic mechanism of dihydromyricetin.Results In the MTT assay,dihydromyricetin 50?mol?L-1 significantly inhibited survival ratios of AGZY-83-a cells at dose-and time-dependent manner.It was demonstrated in TUNEL assay that dihydromyricetin could induce the apoptosis of AGZY-83-a cells in a concentration-dependent manner.The examination of Caspase-3 activity indicated that the dihydromyricetin could induce the apoptosis of AGZY-83-a cells,which was dose-dependent activation of Caspase-3 in AGZY-83-a cells.The detection of the intracellular i showed that the average FI of the i could be markedly increased to 20-fold as the basic condition.Conclusions Dihydromyricetin can induce the apoptosis in AGZY-83-a cells,which is associated with the overload of the intracellular i.