AGE RELATED CHANGES IN THE RESPIRATORY PHYSIOLOGY OF FLIGHT MUSCLE FROM THE BLOWFLY, CALLIPHORA ERYTHROCEPHALA

Measurements of oxygen uptake have been made on preparations of blowfly thoracic flight muscle as a function of age, under four different experimental conditions. The results in all cases showed a significant increase in oxygen uptake with age from a value of about 10-11 mu lO(2)mg/dry wt. muscle/hr in preparations from 7-day-old flies to between 18-19 mu lO(2)/mg dry wt. muscle/hr in preparations from 85-day-old flies. These results confirmed earlier findings with the whole animal at rest. Measurements made with 2 per cent serum albumin in the incubation medium support the idea that partial in vivo uncoupling is taking place in old tissues which could change the ADP/ATP ratio and as a consequence increase the QO(2). Alternative factors, which might contribute to the observed elevation in QO(2) are also discussed.