| Partâ… Effect and Mechanism of Myocardial protection for Diazoxide Pretreatment in Rats with Severe Acute PancreatitisObjective:Opening MitoKATP channel with diazoxide pretreatment to simulate myocardial ischemic preconditioning against myocardial ischemic injury,this study detected the changes of serum CK-MB,LDH, myocardial cell Na+-K+-ATPase activity,mito-chondrial membrane potential and AI in rats of myocardial injury with SAP, so as to better understand the role and its possible mechanism.Methods:36 healthy SD rats were randomly divided into four teams:control group(K group,6 rats),SAP group(M group,10 rats),DZ+SAP group(D group,10 rats) and DZ+5-HD+SAP group(H group,10 rats).SAP model was induced by retrograde infusion of 5% Sodium Cholate into the bile-pancreatic duct.After 3d DZ (20 mg.kg-1.d-1) consecutive intraperitoneal injection,D group was made to SAP model.Consecutive intraperitoneal injection of DZ(20 mg.kg-1.d-1) and 5-HD (20mg.kg-1.d-1) for 3 days,H group was made to SAP model too.The control group didn't inject sodium Cholate, just flipped the pancreas several times.Death rate of each group was recorded at 24 hours after the operation.Blood of all rats was taken from abdominal aorta to detect the levels of serum CK-MB and LDH at 24 hours after the operation.Applied Spectrophotometry to detect Na+-K+-ATPase activity of myocardial tissue.The alteration of mitochondrial membrane potential was detected by flow cytometry.The technique of TUNEL was used to detect myocardial apoptosis. Heart and pancreas was stored to perform histopathologic examination.Results:1. The changes of serum CK-MB and LDH The levels of serum CK-MB and LDH in SAP group were significantly higher than that in control group (P<0.01).Although the levels of serum CK-MB and LDH in D group were higher than that in control group,the decreased difference was statistical significance than SAP group (P<0.011).Comparison between H and D group,the difference has statistical significance(P<0.01),but there were no significant difference with H and M group, indicating 5-HD could block the myocardial protection role of DZ.2. The changes of Na+-K+-ATPase activityIn SAP group,the Na+-K+-ATPase activity was significantly lower than that in control group (P<0.01).The Na+-K+-ATPase activity in D group was obviously higher than that in SAP group(P<0.05).It was significantly lower in H group than that in D group(P<0.05),but the difference was not statistically significant between D and SAP group(P>0.05).3. The changes of mitochondrial membrane potentialThe Rhodamine-123 fluorescent intensity was reduced in SAP group.Comparison between control and SAP group had statistical significance(P<0.01).It was significantly higher in D group than in SAP group(P<0.05).The result in H group was obviously lower than in D group, while the difference was not statistically significant between D and SAP group(P>0.05).This result show that mitochrodrail membrane potential can degrade in myocardial apoptosis.4. The changes of myocardial cell apoptosisThe technique of TUNEL was used to detect myocardial apoptosis,the serious of apoptosis was remarked with apoptotic index.The AI in SAP group was significantly higher than that in control group(P<0.01).Compared with the SAP group,apoptotic index decreased in D group(P<0.01).The AI in H group was significantly higher than that in D group(P<0.05),but there was no significant difference with H and M group.Conclusion:1. SAP associated with severe myocardial damage,myocardial cell energy metabolism, mitochondrial membrane integrity damage and significantly increased cardiomyocyte apoptosis, suggesting that apoptosis is an important mechanism of SAP. 2. The myocardial protective effect by DZ pretreatment was significant.It can resist myocardial ischemia,reduce the leakage of myocardial enzymes,enhance mitochondrial Na+-K+-ATPase activity and prevent mitochondrial calcium overload, thus to maintain the stability of matrix sizes.It also can maintain mitochondrial membrane integrity, reduce the loss of membrane potential and against myocardial cell apoptosis.MitoKATP channel blocker 5-HD could inhibit the cardioprotective effects of DZ.3. DZ pretreatment provides a new treatment idea for SAP, and provides an important basis for post-processing. Partâ…¡Effect and mechanism of myocardial protection for Chinese Herbs in rats with Severe Acute PancreatitisObjective:To syudy the effect of Shenqi Fuzheng Injection on serum CK-MB,LDH, Na+-K+-ATPase activity,AI,mitochondrial membrane potential and heart injury on rats of SAP, so as to better understand the role and its possible mechanism.Methods:26 healthy SD rats were randomly divided into three teams:control group(K group, 6 rats),SAP group(M group,10 rats) and Shenqi Fuzheng Injection group(S group,10 rats).SAP model was induced by retrograde infusion of 5% Sodium Cholate into the bile-pancreatic duct in M and S group.In S group,all rats were treated by intraperitoneal injection of homologous Chinese herbs (2.5ml/100g) at 8 hour and 16 hour after operation,while in K and M groups, all rats were treated by intraperitoneal injection of normal sodium (2.5ml/100g) at the same time.Death rate of each group was recorded at 24 hours after the operation.Blood of all rats was taken from abdominal aorta to detect the levels of serum CK-MB and LDH at 24 hours after the operation. Applied Spectrophotometry to detecte Na+-K+-ATPase activity of myocardial tissue.The alteration of mitochondrial membrane potential was detected by flow cytometry.The technique of TUNEL was used to detected myocardial apoptosis. Heart and pancreas was stored to perform histopathologic examination.Results:The levels of serum CK-MB and LDH,the heart pathological scores and the myocardial apoptosis in S group were lower than that in M group (P<0.01) but remain higher than that in K group (P<0.01),while the Na+-K+-ATPase activity and mitochondrial membrane potential were higher than that in M group (P<0.05) but remain lower than that in control group (P<0.01). Conclusion:Shenqi Fuzheng Injection used in the early stage of SAP can down-regulate the expression of serum CK-MB and LDH and lessen heart pathological lesion, which tentative confirm the therapeutic effect of it on the myocardial protection of SAP. Shenqi Fuzheng Injection also can enhance the Na+-K+-ATPase activity of myo-cardial tissue,avoid losing mitochondrial membrane potential, thus inhibiting myocardial apoptosis. |
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