Effects of maternal calorie-restricted diet on development of the foetal heart, as evaluated in primary cultures of rat myocardial cells.

Very-low-calorie diets have been implicated in causing ventricular arrhythmias and sudden cardiac death. Furthermore, studies indicate that maternal carbohydrate-restricted diets consumed during pregnancy and lactation reduce foetal growth, parturition and postnatal survival of rat pups. In this study, Sprague-Dawley rats were maintained on a semi-purified full-calorie or 50% carbohydrate-calorie-restricted diet throughout pregnancy. The function and integrity of myocardial cell cultures obtained from 3-5-day-old offspring from both groups of dams were evaluated after a drug-induced toxic challenge. After the myocytes had been in culture for 4 days, they were exposed to various concentrations of amitriptyline (1 x 10(-3) to 1 x 10(-5) M). Morphology, beating activity, lactate dehydrogenase release, glucose utilization, beta-adrenergic receptor [125I]iodopindolol binding, and cellular adenosine triphosphate content were evaluated for 24 hr after drug exposure. There were no significant differences in morphology, beating activity or glucose utilization between the full-calorie and calorie-restricted groups. When compared with the full-calorie group, lactate dehydrogenase release from the calorie-restricted group was significantly lower at 8 hr for the untreated controls and those cells exposed to 1 x 10(-4) and 1 x 10(-5) M-amitriptyline. Adenosine triphosphate levels were lower in untreated controls from the calorie-restricted group when compared with the full-calorie group at 4 hr. Within the calorie-restricted group, those cultures exposed to 1 x 10(-4) M-amitriptyline had significantly depressed adenosine triphosphate levels after 8 hr of drug treatment when compared with their respective untreated controls. Finally, the calorie-restricted group had significantly increased binding affinities of beta-receptors. Thus, maternal consumption of calorie-restricted diets during pregnancy may affect the myocardial functional capacity and integrity of the offspring.

Ethanol lowers heart carnitine in the methionine and choline deficient rat.

In agreement with the findings of others, heart carnitine levels of male, weanling Sprague-Dawley rats fed nutritionally adequate liquid diets with 35% of calories as ethanol for 3 weeks were not different from control or pair-fed rats (Experiment 1). When ethanol was given as 30% of energy in combination with a diet deficient in methionine and choline, and the feeding period was extended to 5 weeks, heart carnitine levels were significantly affected (Experiment 2). Carnitine levels in whole heart homogenates of the methionine and choline deficient chronic ethanol-fed group were 2.14 +/- 0.74 mumoles per g dry wt. significantly lower (p less than 0.05) than deficient controls, 3.08 +/- 0.85 mumoles per g dry wt. We conclude that a methionine and choline deficient diet exacerbates the effects of alcohol on methyl-group metabolism so as to produce decrements in heart carnitine not seen when alcohol is given with an adequate diet.

Measurement of the D(s)+ lifetime.

A high statistics measurement of the D(s)+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, D(s)+ --> phi(1020)pi+ and D(s)+ -->K*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5(stat) +/- 5.1(syst) fs using 8961 +/- 105 D(s)+ --> phi(1020)pi+ and 4680 +/- 90 D(s)+ --> K*(892)0K+ decays. This is a significant improvement over the present world average.