ABSTRACT
Objective To study the influence of arachidonic acid (AA) on L-type calcium channel in rabbits sin-gle cardiomyocyte and its mechanism of antiarrhythmia. Method The single ventricular cardiomyocyte was isolat-ed by using enzyme dispersion method and whole-cell clamp-patch technique was used to record L-type calcium current.All data were analyzed using ANOVA. Results AA inhibited Ica-L in a concentration-dependent manner. The application of 3 μmol/L, 10 μmol/L and 20 μmol/L arachidonic acid reduced the density of peak Ica-L from (10.79±0.93)pA/pF to (8.99±0.43)pA/pF to (7.60±0.35)pA/pF and to (5.60±0.30)pA/pF, respctive-ly (n=7, P<0. O1 ). The Ica-Lpartially resumed after washout. The AA up-shifted the I-V curves of Ica-L without changes of their shape,peak and reverse potentials. The AA also markedly shifted the inactivation curve to left, and prolonged the recorvery time from inactivation,but did not change the curve of calcium channel activation. Con-clustions By acceleration of L-type calcium channel inactivation and prolongation of recorvery time from inactiva-fion,arachidonic acid can reduce the calcium ion influe and prolong effective refractory period, playing the role of antiarrhythmia.
ABSTRACT
ObjectiveTo investigate clinical characteristics and perioperative management of abdominal aortic aneurysm in elderly patients. MethodsThe clinical data of 24 patients aged 60 years and over with abdominal aortic aneurysm in our hospital were analyzed retrospectively. ResultsThe average age was 75.5 years and the proportion of male and female was 5 : 1. The course of disease was 2 days to 15 years and the median course was 2.8 months. 17 patients were complicated with hypertension, 5 patients with coronary heart disease, 4 patients with type 2 diabetes mellitus, 3 patients with chronic bronchitis, 2 patients with lacunar cerebral infarction, 3 patients with abdominal aortic aneurysm rupture, 13 patients with endovascular stent grafts, 10 patients with abdominal aortic aneurysm resection and artificial vascular replacement, 1 patient with endovascular stent grafts, endarterectomy of right femoral artery and right deep femoral artery,right deep femoral artery plasty and the application of artificial blood vessel in right femoro-popliteal arterial bypass. Postoperative complications happened in 15 cases (62.5%, 15/24) and the postoperative mortality rate was 20.8%.ConclusionsThe elderly patients with abdominal aortic aneurysm are always complicated with manyother chronic diseases such as hypertension, coronary heart disease , diabetes mellitus, chronicbronchitis. The operation for abdominal aortic aneurysm in elderly patients has high risk. Reasonablesurgical procedure and active perioperative management are the key for successful treatment.
ABSTRACT
AIM: To study the influence of arachidonic acid(AA) on the action potential and L-type calcium current in rabbit cardiomyocytes.METHODS: Single ventricular myocyte was isolated using enzyme dispersion method.Whole-cell clamp-patch technique was used to record action potential and L-type calcium current.RESULTS: ① AA shortened action potential duration obviously,without marked effect on the resting potential and action potential amplitude.② AA reduced the current densities from(10.21?3.15)PA/PF to(6.53?2.17)PA/PF(n=6,P