The Regulation Of Dids On Pi3k/akt And Ros In The Ischemia-reperfusion Injury Myocardial

Ischemia / reperfusion injury (I / RI), closely related to the intracellular acidosis, Ca²⁺ overload, is an important injury mechanism of thrombolysis of acute coronary thrombosis, percutaneous coronary intervention (PCI) and coronary artary bypass graft(CABG). Rencent evidence suggests that burst production of reactive oxygen species (ROS) from mitochondria is closely related to cell damage and apoptosis during I/RI. A large number of ROS causes irreversible damage to mitochondrial function, leading to myocardial cell death. In addition, I/RI dephosphorylates p-Akt, which is a protective signal transduction pathway, and ultimately leads to cell apoptosis. Our previous study has confirmed that non-specific chloride channel blocker DIDS could inhibit apoptosis induced-by I/RI. However, the mechanism remains to be investigated. In this context, to study the mechanism of DIDS involved in cardioprotection of I/RI, we monitored its effects on the expression of ROS. In addition, we assessed whether the effects of DIDS to I/RI is associated with activation of the PI3K/Akt prosurvival pathway.Objective1. To observe the effects of DIDS on the expression of I/RI-induced superoxide dismutase (SOD), malondialdehyde (MDA) and ROS.2. To monitor the regulation of the chloride channel blocker DIDS on the expression of I/RI-induced PI3K/Akt signaling molecules and ROS.MethodsMale SD rats were divided into four groups(n=8), named sham operation group, I/R group, catalase(CAT) group and DIDS group, respectively. The area of myocardial infarction was detected by double-staining of Evans blue and red tetrazolium (TTC). We used fluorescence spectrophotometer to monitor the concentration of ROS from myocardial tissues. Meanwhile, we detected the levels of serum creatine kinase (CK) and lacate dehydrogenase (LDH), malonaldehyde (MDA) and superoxide dismatast (SOD). In addition, the cardiomyocyte apoptotic index and the expression of total Akt and phosphorylated-Akt were detected by TUNEL and Western blot, respectively.Results1. Compared with the I/R group, the area of myocardial infarction from DIDS group and CAT group was significantly decreased (P<0.05). However, the difference between DIDS and CAT group was not significant (P> 0.05). 2. Compared with the I/R group, DIDS group and CAT group significantly decreased the expression of CK, LDH (n=8, P<0.05); while DIDS group and CAT group had no significant difference(P> 0.05).3. In contrast with I/R group, TUNEL assay shows that DIDS group and CAT group significantly decreased the apoptotic index of cardiomyocytes (P <0.05). DIDS, CAT groups decreased significantly (P < 0.05), but DIDS and CAT had no significant difference (P> 0.05).4. the results of serum SOD activity, compared with the sham group, I / R, DIDS, and CAT were significantly lower (P <0.05); and compared with the I / RI group, DIDS, CAT group were significantly higher (P <0.05) , CAT group increased more significantly than the DIDS group (P <0.05).5. the results of serum MDA levels, compared with the sham group, I / R, DIDS, and CAT were significantly increased (P <0.05); and compared with the I / R group, DIDS, CAT groups decreased significantly (P <0.05), CAT group decreased more significantly than the DIDS group (P <0.05).6. The myocardial ROS levels, compared with the sham group, I / R, DIDS, and CAT were significantly increased (P <0.05); and compared with the I / R group, DIDS, CAT groups decreased significantly (P < 0.05), CAT group decreased more significantly than the DIDS group (P <0.05).7. Myocardial total Akt in each group had no significant difference (P> 0.05). But the p-Akt were different. Compared with the sham group, p-Akt levels of I / R, DIDS, and CAT were higher (P <0.05); p-Akt levels of DIDS group were significantly higher than that of I / R and the CAT group (P < 0.05), I / R and CAT had no difference between (P> 0.05). Conclusion1. DIDS can inhibit ROS levels, increased serum SOD activity and lower MDA, to achieve the protection of I / RI myocardium.2. CAT scavenging reactive oxygen species can directly reduce the I / RI of myocardial injury, to protect the myocardium.3. DIDS and CAT both can inhibit reactive oxygen species and active PI3K/Akt signaling pathway to protect the myocardium.