AGE-RELATED-CHANGES OF AMP BREAKDOWN IN CHICKEN HEART

The activity of adenylate deaminase, adenylate phosphatase and adenosi ne deaminase, as well as the endogenous content of adenine nucleotides , was examined in the heart of ageing chickens. In new-born (1-day-old ) and young (20-day-old) chickens, AMP degradation in the heart seems to proceed preferentially through deamination, while in adult (1-year- old) through dephosphorylation. Compared with the adult heart, a 2-yea r-old one exhibits a decline of AMP catabolism. The total adenine nucl eotide content and the concentration of ATP are higher in adult and ag ed chicken hearts, than in new-born and young ones. Adaptive mechanism s might occur in the heart of ageing chickens to ensure an adequate av ailability of adenine nucleotides.