Avian phosphoenolpyruvate carboxykinase: effect of age, starvation and photoperiod

Computer analysis of the subcellular distribution of phosphoenolpyruvate carboxykinase in adult female (Gallus domesticus) chicken liver indicates that the activity is distributed between the mitochondria and nucleus in the ratio 70: 30%. There was no activity found in the cytosol. Newly hatched chicks and 8-week-old juveniles were found to have a significant soluble hepatic PEPCK activity. The particulate activity of PEPCK in the livers of juveniles raised in continuous light (24L:0D) decreased over the course of a 7-day fast while no such decrease was seen in juveniles raised in a 12-hr daylength photoperiod (12L:12D).