SUMMARYThis study was performed to investigate the prophylactic effect of disopyramide phosphate on ventricular fibrillation in acute myocardial infarction. Lidocaine and disopyramide phosphate were compared in terms of their effects on the lowered ventricular fibrillation threshold in experimental myocardial infarction produced by coronary ligation in dogs. The following results were obtained:1) The effect of lidocaine i.v.+infusion appeared promptly and the ventricular fibrillation threshold exceeded control levels from 45min onwards (p<0.01).2) The i.m. injection of lidocaine was effective in a dose of 10 mg/Kg. The minimally effective blood level was 1.7mcg/ml.3) Disopyramide phosphate 5mg/Kg i.v. produced a tendency towards recovery from 15min onwards. After 30min, the ventricular fibrillation threshold was significantly higher than control (p<0.01). 4) Disopyramide phosphate 5mg/Kg i.m. was initially effective after 45min. The effect was significant from 1 hour and 30min onwards, compared with control (p<0.01). The minimally effective blood level was 2.4mcg/ml. 5) Disopyramide phosphate 2mg/Kg i.m. produced a tendency towards recovery but the difference from the control was not significant. 6) In equivalent i.m. doses, disopyramide phosphate tended to be more potent than lidocaine in increasing the ventricular fibrillation threshold.7) In the aforementioned doses, disopyramide phosphate did not cause any marked changes in PQ interval or QT time in ECG.These results suggest that the intramuscular injection of disopyramide phosphate is a hopeful clinical treatment to prevent ventricular From the First
SummaryWe studied the effect of hypoxia on lipid accumulation in cultured Fibroblasts from normal rabbits (normal fibroblasts) and in low density lipoprotein (LDL) receptor-negative fibroblasts from WHHL (Watanabe heritable hyperlipidemic) rabbits (WHHL fibroblasts). These cells were incubated in medium with normolipemic rabbit serum (NRS) or hyperlipemic rabbit serum (HRS). The cells were incubated in a humidified atmosphere of either 20% O2, 75% N2, and 5% CO2 (control cells) or 2% O2, 93% N2, and 5 % CO2 (hypoxic cells).After 48 h incubation of normal fibroblasts in medium with 20/ NRS, free fatty acid (FFA) levels were increased slightly and the triglyceride (TG) level markedly in hypoxic cells. In the medium with 20% HRS, in addition to the increased FFA and TG levels, the free cholesterol level was increased slightly and the esterified cholesterol level markedly in hypoxic cells. Moreover, in WHHL fibroblasts, which lack LDL receptors, cellular lipid accumulation was also observed after 48 h incubation in the medium with 20% HRS, and hypoxic incubation enhanced the cellular cholesterol and TG accumulation, as in normal fibroblasts.These results suggest that under hyperlipemic conditions, non LDL receptor-mediated uptake of lipoproteins plays a major role in cellular lipid deposition and that tissue hypoxia promotes lipid accumulation in peripheral cells by the LDL receptor-independent mechanisms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.