ABSTRACT
<p><b>OBJECTIVE</b>To explore the antiarrhythmic mechanism of ampelopsin through electrophysiological study in rats.</p><p><b>METHODS</b>The in vivo experimental groups were as follows:control group, low-dose, middle-dose and high-dose group. Arrhythmia in rats was induced by aconitine injection, and then the antiarrhythmic effects of ampelopsin were studied. Cardiomyocytes were isolated from rats therafter. The whole-cell patch-clamp technique was used to record action potential duration (APD), sodium currents (INa), calcium current (ICa), transient outward potassium currents (Ito) and inward rectifier potassium currents (IK1) in cardiomyocytes.</p><p><b>RESULTS</b>In vivo experiments showed that the incidence of aconitine-induced experimental arrhythmias in low, middle and high-dose ampelopsin group was significantly lower than that in control group (n = 5 each group, all P < 0.05). In vitro whole-cell patch clamp experiments showed that action potential duration in low, middle and high-dose groups was significantly shorter than that in control group, and amplitude of action potential was also significantly lower in low, middle and high-dose ampelopsin groups than in control group (134.1 ± 6.9), (120.1 ± 7.4), (113.2 ± 9.0), and (101.8 ± 5.1) mV for control, low, middle and high-dose group (n = 9 each group, all P < 0.05).Further research revealed that sodium currents in cardiomyocytes were decreased by low, middle and high-dose ampelopsin from (-36.75 ± 3.60) to (-31.03 ± 2.61), (-26.63 ± 3.72), and (-17.55 ± 4.43) pA/pF (n = 9 each group, all P < 0.05), but the activation voltage for peak potential was not affected by ampelopsin. Moreover, the inward rectifier potassium current was also higher in high-dose ampelopsin group than in control group (P < 0.05). Calcium current and transient outward potassium current were similar among four groups.</p><p><b>CONCLUSION</b>Ampelopsin exerts anti-arrhythmic effects in this rat model, and the underlying electrophysiological mechanism is partly associated with the inhibition of INa and enhancement of IK1, and prolongation of APD.</p>
Subject(s)
Animals , Rats , Action Potentials , Anti-Arrhythmia Agents , Pharmacology , Arrhythmias, Cardiac , Flavonoids , Pharmacology , Myocytes, Cardiac , Patch-Clamp Techniques , Potassium ChannelsABSTRACT
Objective: To study the nursing of patients with morbid obesity treated with laparoscopic vertical banded gastroplasty (LVBG). Methods: Before operation, obese degree, obesity-related conditions and mental states were examined routinely. Monitoring of respiratory tract, observing operative complications and instructing of diets were done after operation. Results: Among 6 patients, 5 were at the third degree of obese, one was at second. In obesity-related conditions, 4 patients had hypertension and acantha derma, 1 had arthritis, and all had respiratory sleeping syndrome. The operations were all successful. The food amount food and body weight both decreased significantly 1 month after operation. The common operative complications were mild bleeding (1 case), shoulder-back pain (1 case), nausea and vomiting (5 cases). Diet principle was high protein, low energy, liquid food was the first choice. Conclusion: Observing and preventing respiratory sleeping syndrome are the main points of postoperative cares. Instructing patients to establish correct diet habit is the key to reach the best efficacy of LVBG.