FLIGHT EFFECTS ON CERTAIN BLOOD PARAMETERS IN HOMING PIGEONS COLUMBA-LIVIA

1. Various blood parameters were monitored in resting and flown homing pigeons. A homing flight of 48 km lasting 60-80 min did not significa ntly alter plasma levels of total protein, electrolytes and plasma osm olality, which indicated maintenance of the homeostatic stability of t he internal milieu during moderate exercise. 2. Plasma concentrations of marker enzymes such as alanine aminotransferase (ALAT), aspartate a minotransferase (ASAT), lactate dehydrogenase (LDH) and creatine phosp hokinase (CPK) that tend to denote muscle damage and metabolic flux in prolonged exercise, were also not altered, thereby indicating the ste ady state of tissue structure and function during a flight of this mag nitude. 3. Significant increases in plasma levels of uric acid and cre atinine and decreases in plasma albumin were observed in the flown pig eons. 4. The flight-induced increase in blood uric acid could be attri buted to increased purine catabolism and the increase in creatinine to increased nucleotide turnover. 5. It is suggested that the higher uri c acid levels should not only enhance water conservation, but may also reduce flight-induced hyperthermia besides acting as an antioxidant d efence against oxidative tissue injury. 6. The rise in creatinine is i ndicative of the breakdown of phosphocreatine for energy during the in itial period of flight prior to the utilization of carbohydrate and li pid as fuels. 7. The decrease in plasma albumin should account for the albumin as lipid carrier lost in transport to the muscles during flig ht.