Effects of undernutrition on glycine metabolism in the cerebellum of rats.

Undernutrition is a worldwide problem affecting millions of unborn and young children during the most vulnerable stages of brain development. Total restriction of protein during the perinatal period of life can alter the development of the mammalian fetus and have marked repercussions on development of the central nervous system (CNS). The brain is vulnerable to undernutrition with altered morphologic and biochemical maturation, leading to impaired functions. The focus of this study is to investigate [U-14C]glycine metabolism in undernourished rats submitted to pre- and postnatal protein deprivation (diet: 8% protein with and without addition of L-methionine; control group: 25% protein). Although undernutrition produced a reduction in cerebellar weight and alterations in the DNA concentration, the present study shows that glycine metabolism in this structure is partially protected because the undernourished group with L-methionine did not show modifications in glycine metabolism at all ages studied. However, L-methionine deficiency alters glycine metabolism at 7 and 21 days, but in the adult age both undernourished groups presented no differences in oxidation to CO2, conversion to lipids and incorporation into protein from glycine, compared to the control group.

Serum and liver lipids in rats and chicks fed with diets containing different oils.

OBJECTIVES: Because dietary fat composition is determinant for serum cholesterol level, which is related to cardiovascular disease, we evaluated the effects of diets containing saturated (coconut oil) or polyunsaturated fatty acids (soybean oil) supplemented or not with dietary cholesterol on serum and liver lipid composition in two animal species. METHODS: Male Wistar rats (21 d old) were assigned to one of seven groups and fed with commercial diet or diets containing 5% or 20% soybean oil or 20% coconut oil with or without 1% cholesterol. Chicks were assigned to one of four groups and fed with diets containing 15% soybean oil or 15% coconut oil with or without 1% cholesterol. RESULTS: In rats, the accumulations of hepatic cholesterol and triacylglycerols were higher in the group fed 20% soybean oil and 1% cholesterol than in the group fed 20% coconut fat and 1% cholesterol. The highest serum levels of cholesterol and triacylglycerols were observed in the group fed coconut oil and cholesterol, compared with the group fed soybean oil and cholesterol. Triacylglycerol, high-density lipoprotein, and total cholesterol serum levels increased with diet containing coconut oil and cholesterol. In chicks, the highest hepatic cholesterol accumulation occurred in the group fed 15% coconut fat and 1% cholesterol. Total and high-density lipoprotein cholesterol levels increased with diet containing coconut oil and cholesterol, although none of these diets modified serum triacylglycerol levels. CONCLUSIONS: The type of experimental animal model and the diet composition influence lipid metabolism.

Effects of undernutrition on glutamatergic parameters in rat brain.

Early restriction of nutrients during the perinatal period has marked repercussions on CNS ontogeny, leading to impaired functions. This study investigated the effects of pre- and postnatal (up to 75 days) undernutrition (diet: 8% protein; normonourished group: 25% protein) on some glutamatergic and behavioral parameters of rats. Undernutrition reduced: (i) seizures caused by ICV quinolinic acid (QA) administration; (ii) Na-independent [3H]glutamate binding in cell plasma membranes of cerebral cortex, and (ii) basal [3H]glutamate release from synaptosomal preparation. Behavioral parameters related to locomotion, anxiety, or memory were not affected. These results indicate that our model of undernutrition decreased the sensitivity to QA as convulsing agent and point to some putative glutamatergic parameters involved in this effect.