EFFECTS OF STRESS ON AMINO-ACIDS AND RELATED-COMPOUNDS IN VARIOUS TISSUES OF FASTED RATS

The purpose of this study was to examine the effect of stress on the f ree amino acid pattern of plasma and various organs. Two groups of rat s were deprived of food, for 24 hrs. One group was sacrificed after th is time (fasting control representing mostly free endogenous amino aci ds) and the second group was first restrained in wire cages for 120 mi n before being sacrificed.(fasting stress representing mostly the effe cts of stress on; endogenous free amino acids). A third group had free access to food and was sacrificed at the same time (fed control repre senting mostly free amino acids absorbed from the gut and endogenous f ree amino acid metabolism). Fasting(as compared to fed controls) reduc ed alanine and arginine but increased ethanolamine, glutamic acid and glutamine in the plasma; increased ethanolamine, phosphoethanolamine a nd glutamic acid in the liver; increased camosine, glutamic acid, phos phoethanolamine and glutamine in the ventricle; increased oxidized glu tathione in the aorta; decreased alanine, aspartic acid, glutamic acid , leucine and methionine and increased glutamine in the pancreas; and decreased arginine in skeletal muscle. Fasting plus stress (as compare d to fasting controls) reduced alanine and glutamine in the plasma; in creased methionine in the liver; increased ethanolamine, GABA, and glu tamic acid in the aorta; reduced arginine, glutamic acid, glutamine, l eucine and methionine but increased ethanolamine in the ventricle; red uced ammonia and ethanolamine but increased histidine, isoleucine, leu cine, lysine, phenylalanine, tyrosine and valine in the pancreas; and reduced ammonia in skeletal muscle. Fasting plus stress affects the am ino acid composition of plasma and various of tissues but effects seen were individually different and strongly substance and tissue specifi c. Plasma changes did not coincide with tissue changes. Changes in the endogenous pattern of amino acids and related compounds in response t o stress could be first indications of stress induced organ pathology.