Changes in the acinar activity patterns of phosphoenolpyruvate carboxykinase in livers of male and female rats upon feeding a high protein and a high fat diet.

Phosphoenolpyruvate carboxykinase (PEPCK) activity was investigated in relation to its localization within the liver acinus of male and female rats after feeding either a high protein diet (77%) or a high fat diet (52%). Both diets led to sex-dependent changes in activity and acinar distribution patterns. In male rats high protein diet provoked a shift in the acinar activity pattern towards the perivenous parts of the acinus without increase in average activity. Yet in the livers of females the activity was increased in all parts of the acinus, but to a greater extent in the perivenous parts of the acinus. Feeding a high fat diet increased PEPCK activity in males and to an even greater extent in females. In both sexes the increase was greater in the perivenous zone when compared to the changes within the periportal zone. The results are discussed in relation to changes in the concentrations of glucoregulatory hormones.