THE EFFECTS OF STARVATION ON PLASMA-FREE AMINO-ACID AND GLUCOSE-CONCENTRATIONS IN LAKE STURGEON

The effect of starvation on the metabolism of the lake sturgeon Acipen ser fulvescens was examined by measuring haematocrit, plasma glucose c oncentrations, and plasma free amino acids. Plasma was sampled on day 0, 10, 20, 45 and 60 of a 60-day starvation period. Haematocrit was ob served to decrease with starvation indicating a decreased oxygen carry ing capacity of the blood. Plasma glucose levels differed only at day 10, with a decrease in blood glucose level in the starved group. No di fferences were detected between groups for alanine, aspartate, and ser ine, while elevated levels were observed for glutamine throughout the experiment. An increase in arginine, tyrosine, valine, methionine, try ptophan, phenylalanine, glutamate, glycine, isoleucine, histidine and leucine, concentrations were observed after 45 days of starvation. The maintenance, or increased plasma levels, of glucogenic amino acids in combination with the maintenance of blood glucose concentrations indi cates active gluconeogenic processes in the liver supported by muscle proteolysis. (C) 1996 The Fisheries Society of the British Isles