Effect of Early Protein-Energy Malnutrition and Environmental Changes on Cholinesterase Activity of Brain and Adrenal Glands of Rats

Abstract

The effect of nutritional-environmental interaction on cholinesterase (ChE) activity of brain and adrenal glands of rats was investigated. Malnutrition was induced by feeding a low protein purified diet to lactating dams thus reducing milk supply for suckling pups, and after weaning at 3 weeks of age a low protein diet was fed for an additional 4 weeks followed by a high protein diet for rehabilitation. This optimal diet was fed to controls throughout the study. Three levels of environmental manipulation, normal, isolated and enriched, were provided to each of the dietary groups during the first 7 weeks of life after which normal conditions of both diet and environment were followed until the study was terminated at 20 weeks of age. Consistent with previous findings, early protein-energy malnutrition resulted in long-lasting elevation of brain ChE activity. In control-fed rats, environmental isolation resulted in increases in ChE specific activity, whereas, in early malnourished rats, isolation led to lowered ChE activity. Environmental enrichment did not affect ChE in control-fed rats and as a result, ChE specific activity of enriched animals was lower than was found in isolated animals. Adrenal ChE activity was increased in previously malnourished rats. No further increase was noted due to environmental manipulation, but in control-fed rats both enriched and isolated animals had elevated adrenal ChE activity.