The Effects of Na~+/Ca~(2+) exchange (NCX) on the Repolarization of Canine Ventricular Myocyte-Potential Arrhythmogenic Effect of NCX during a Mis-matched Repolarization and Relaxation Xiamen Zhongshan Hospital, Xiamen Medical College, Xiamen University

The Effects of Na~+/Ca~(2+) exchange (NCX) on the Repolarization of Canine Ventricular Myocyte-Potential Arrhythmogenic Effect of NCX during a Mis-matched Repolarization and Relaxation Xiamen Zhongshan Hospital, Xiamen Medical College, Xiamen University@巩燕$Visiting scholar of cardiac arrhythmia research institute,university hospital of Oklahoma!U.S.A @王焱 @BELA Szabo$Basic cardiac research laboratory,cardiac arrhythmia research institute,university hospital of Oklahoma!…     

Adenosine deaminase and purine nucleoside phosphorylase activity in spleen cells of aged mice

The activities of two enzymes of purine metabolism, adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP), were determined in spleen lymphocytes from mice of various ages. We found that in the older animals, which have depressed responses to concanavalin A and phytohemagglutinin, there is a decrease in the activity of PNP but normal activity of ADA. The decline of PNP activity was seen at 7.5 months of age and appears to be concurrent with a decline in T-cell function. These results suggest that a decrease in PNP activity may be a contributing factor in the immunodeficient state of the aged.     

Effect of insulin in vitro on the isolated,perfused alloxan-diabetic rat liver

Summary Withdrawal of exogenous insulin and a subsequent fast (24 h) of alloxan diabetic rats stimulated rates of gluconeogenesis, ureogenesis, ketogenesis, and amino acid release by in situ perfused livers when compared to those from normal, fasted rats. The contribution of liver glycogen to the high rates of gluconeogenesis observed with the diabetic liver could be excluded. Perfusate lactate concentrations remained constant during the period when the elevated rate of gluconeogenesis was observed with diabetic liver. Addition of insulin as a bolus (750 mU) and continuous infusion (12.5 mU/min) to the perfusion medium of diabetic livers resulted in constant perfusate levels of glucose, urea and -amino nitrogen indicating a suppression of the catabolic processes present in the fasted, diabetic liver. The rate of ketogenesis was also slowed by insulin to about half the rate prior to addition of the hormone. These data indicate that insulin has an immediate anti-catabolic effect in the perfused, diabetic liver.