Ameliorative effect of sevoflurane on endoplasmic reticulum stress mediates cardioprotection against ischemia-reperfusion injury 1.

We aimed to investigate whether the cardioprotection of sevoflurane against ischemia-reperfusion (IR) injury is via inhibiting endoplasmic reticulum stress. The rat in vivo model of myocardial IR injury was induced by ligation of the left anterior descending coronary artery. Sevoflurane significantly ameliorated the reduced cardiac function, increased infarct size, and elevated troponin I level and lactate dehydrogenase activity in plasma induced by IR injury. Sevoflurane suppressed the IR-induced myocardial apoptosis. The increased protein levels of glucose-regulated protein 78 and C/EBP homologous protein (CHOP) after myocardial IR were significantly reduced by sevoflurane. The protein levels of phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (PERK), phosphorylated eukaryotic initiation factor 2 (eIF2α), and activating transcription factor 4 (ATF4) were significantly increased in rats with IR and attenuated by sevoflurane treatment. The phosphorylation of Akt was further activated by sevoflurane. The cardioprotection of sevoflurane could be blocked by wortmannin, a PI3K/Akt inhibitor. Our results suggest that the cardioprotection of sevoflurane against IR injury might be mediated by suppressing PERK/eIF2a/ATF4/CHOP signaling via activating the Akt pathway, which helps in understanding the novel mechanism of the cardioprotection of sevoflurane.

[Effects of astragalus injection on renal function in patients after cardiac valve replacement with cardiopulmonary bypass].

OBJECTIVE: To observe the effects of Astragalus Injection (AI) on renal function in patients after cardiac valve replacement with cardiopulmonary bypass (CPB). METHODS: Forty patients scheduled to receive cardiac valve replacement with CPB were randomly assigned to 2 groups equally, the control group and the AI group. Patients in the AI group were administered with AI 40 mL before anesthesia by diluting it in 250 mL 5% glucose solution via intravenous dripping, 20 mL by adding it into the priming solution before CPB and 40 mL once a day diluted as before via intravenous dripping at the foremost 5 successive days after operation. For patients in the control group, equal volume of Ringer's Liquid was given instead of AI. Peripheral blood sample and urine were collected at various time points: before anesthesia (T0), the 1st (T1), 3rd (T3), 5th (T5) and 7th day (T7) after operation, for determining blood levels of urea nitrogen (BUN), creatinine (Cr) and beta2-microglobulin (beta2-MG), as well as urinary levels of beta2-MG, microalbumin (m-Alb) and N-acetyl-D-glucosaminidase (NAG). RESULTS: As compared with those at T0, in the control group, BUN, Cr at T1 and T3, serum beta2-MG at T3, urinary beta2-MG m-Alb and NAG at T1-T7 were significantly higher, while in the AI group, urinary m-Alb, NAG at T1-5 n and urinary beta2-MG at T1-7 were higher (P < 0.05). As compared with those in the control group, serum BUN at T1-3., Cr and blood beta2-MG at T3, urinary beta2-MG, m-Alb and NAG at T1-7 were lower (P < 0.05) in the AI group. CONCLUSION: CPB could induce renal failure, and applying AI at the perioperative stage can protect renal function to some certain extent.

[Myocardial protective effect of Shenfu injection in patients undergoing valve replacement].

OBJECTIVE: To investigate the myocardial protective effect of Shenfu injection in patients undergoing valve replacement. METHODS: Forty patients undergoing valve replacement surgery under cardio-pulmonary bypass (CPB) were randomly divided into two equal groups: group C (control group, given with 4:1 blood containing cardioplegic liquid during the CPB) and group SF (Shenfu injection, receiving the blood containing cardioplegic liquid with 20 ml/L of Shenfu injection additionally). Blood samples were withdrawn from the central vein before operation, 30 minutes after aorta declamping, and 4, 12, and 24 hours after CPB, to test the serum cardiac troponin I (cTnI), creatine phosphokinase (CK), and creatine phosphokinase isoenzyme (CK-MB). RESULTS: The CK, CK-MB, and cTnI level were normal before operation and there were no significant differences in these indexes between the two groups. 30 minutes after aorta declamping, the CK, CK-MB, and cTnI levels were higher than those before operation in both groups (P < 0.05, P < 0. 01), and the higher levels remained to 24 hours after CPB. 24 hours after CPB, the CK level of the group SF was significantly lower than that of the group C (P < 0.05), and 30 minutes after aorta declamping to 24 h after CPB, the CK-MB and cTnI levels were lower in the group SF compared with the group C (all P < 0. 05). CONCLUSION: Shenfu injection decreases the level of CK, CK-MB and cTnI, and reduces the myocardial injury.

[Intracellular dialysis with a microcatheter inserted into the patch-clamp pipette].

In this paper we present an easily available method of intracellular dialysis via a microcatheter inserted into glass pipette during patch clamp experiment. An oblique hole through the glass pipette holder (above the lateral hole for cell-seal suction) is drilled, through which a microcatheter (O.D.=0.1 mm) made from the universal pipetter tip by hand-drawing passes and sticks out of the holder mouth in parallel with the Ag-AgCl electrode. With a syringe connected to the microcatheter, substitution of intracellular solution and intracellular dialysis of drugs can be achieved easily. Compared with repatch technique and intracellular solution substitution techniques used abroad, this method operates more easily and can produce more reliable results.