Restriction of maternal food intake inhibits fatty acid activation in developing rat hearts

Abstract

We studied the effect of restricting the diet of pregnant and lactating rats on the beta-oxidation of fatty acids by the developing heart in suckling pups. Control pregnant rats were fed a stock diet ad libitum. For the experimental group, food was restricted to half of the control intake on the seventh day of pregnancy and continued through lactation. The pups on the restricted diet were significantly smaller than the controls. At postnatal days 5, 14 and 21, the beta-oxidation of [1-14C] palmitate by heart homogenates was determined in the presence of ATP, carnitine and CoA. At day 21, the production of 14CO2 was 60% lower in the group on the restricted diet. Consequently, the possibility of inhibiting activation or intramitochondrial transport of fatty acids by heart mitochondria was studied in vitro using [1-14C] palmitate, [1-14C] palmitoyl CoA and [1-14C] palmitoyl carnitine. With [1-14C] palmitate, the rate of 14CO2 produced was 2464 +/- 317 cpm/mg protein/min for the control and 1682 +/- 91 for the restricted diet group. With [1-14C] palmitoyl CoA and [1-14C] palmitoyl carnitine, the oxidation rate of the experimental group was similar to control values, showing clearly that the inhibition of oxidation was from a problem with activation. A significant decrease in palmitoyl CoA synthetase activity in the heart homogenates and mitochondria of the diet-restricted pups took place.

Ontogeny of Fatty Acid-Activating Enzyme in Rat Liver and Lung

“…It has been shown that liver microsomal FACS activity varies with diet [. 13,14], In accordance with this, a shift from a high fat to a chow diet might have resulted in decreased FACS activity in weaned rats. There is also a possibility of other factors such as hormonal variations influencing the FACS activity after weaning.…”

UDP galactose: Ceramide galactosyltransferase, CDP choline:1, 2‐diacyl‐sn‐glycerol phosphocholine transferase, and microsomal reductases in major regions of the developing rat brain in nutritional stress

“…The observed reductions in the activities of the two cytochrome reductases in brain microsomes could reflect a generalised lowering of activity brought about by decreased availability of long chain fatty acyl CoA's, since these are known to be the true substrates of desaturases (21). Reports exist (22) to indicate that undernutrition does indeed lower the conversion of palmitate to palmitoyl CoA in certain tissues in young rats.…”