ABSTRACT
@#Objective To investigate the effect of adenosine on pulmonary injury after extracorporeal circulation. Methods Twelve mongrel dogs were randomly divided into two groups, the test group and control group. The model of extracorporeal circulation was established. In the test group and control group, adenosine(50μg/kg*min) and normal saline were infused before extracorporeal circulation respectively. Hemodynamics, right cardiac function and arterial blood gas were assessed. Lung water and malondialdehyde content were assessed. Histological evaluation was also made. Results There were no differences between the two groups with respect to heart rate, mean systemic artery pressure, left atrial pressure, and central venous pressure. In the test group, pulmonary vascular resistance was lower and right cardiac function improved remarkably; arterial oxygen pressure (PaO2) was also higher, less lung water was observed and the malondialdehyde content in the pulmonary tissue was lower (P＜0.05,P＜0.01). Histological evaluation of the test group revealed normal pulmonary architecture without abundant intra-alveolar neutrophils. Conclusion Adenosine can attenuate ischemia-reperfusion lung injury and right cardiac insufficiency caused by extracorporeal circulation. At a proper dose, there was no significant effect on systemic hemodynamics.
ABSTRACT
32 Cases of coronary heart diseases (M 20, F 12; age 58+10 y) were treated with polysacchairde sulfate (PSS). PSS 200 mg in 10% glucose solution 500 ml iv, drip, qd, and 14 d, as a course. The results showed; The cardiac function, blood fat and indices of hemorheology were significantly improved ( P
ABSTRACT
AIM: To investigate alteration of inward re ctifier potassium current (I K1) in atrial myocytes and mRNA expression of gene Kir2.1 encoding I K1 in atrial myocardial tissue in patients with chronic atrial fibrillation (AF) compared to that with sinus rhythm (SR).METHODS: Single myocytes were isolated by enzymatic dissociation with the chunk method an d the ionic current was recorded using whole cell patch clamp technique. The sem i-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the mRNA expression of Kir2.1 in atrial myocardial tissue, and the g ene GAPDH was used as an internal control.RESULTS: (1) The I K1 density was increased in AF group at hyperpolarizing pot entials, at -120 mV the current densities was (-5.71?0.65) pA/pF in AF group (n=28 cells from 7 patients) and (-4.26?1.22) pA/pF in SR group (n=35 cells from 9 patients) (P0.05).CONCLUSIONS: The increase in I K1 at hyperpolarizing potentials may be related to th e atrial electrophysiological remodeling in chronic human AF. The increased I K1 density in atrial myocytes in AF group without alteration of Kir2.1 mRNA expression in atrial tissue suggests that I K1 may be mediated at post-transcriptional levels.
ABSTRACT
AIM: To determine the effects of valsartan on calcium channel and sodium-calcium exchanger current in isolated ventricular myocytes of congestive heart failure (CHF) rats. METHODS: Eight weeks after coronary ligation, the rats with heart failure were confirmed by measuring the hemodynamic parameters and divided randomly into the group treating with valsartan (CHF-T, 20 mg/kg) and placebo (CHF-C). Sham-operated group rats served as negative controls (PS). Twelve weeks later, 6 rats were selected randomly for the study of ion channel. Single ventricular myocytes of rats were isolated by enzymatic dissociation. The whole-cell patch-clamp recording technique was used to record calcium channel current and sodium-calcium exchanger current. RESULTS: (1) In the hemodynamic variables, HR and blood pressure were not significantly different in three groups. Compared CHF-C with PS group, LVEDP and Cm increased, LVSP and ?d p /d t max decreased ( P 0 05). (4) Na +-Ca 2+ exchanger current in CHF-C group increased significantly. Na +-Ca 2+ exchanger current in CHF-T group was smaller significantly than that in CHF-C group. However, CHF-T group and PS group were not significantly different. CONCLUSION: Administration of valsartan is effective in preventing from cardiac function deterioration, increases calcium channel current and decreases Na +-Ca 2+ exchanger current in ventricular myocytes of heat failure rats.