Age- and Tissue-specific regulation of chicken inorganic pyrophosphatase

The activities and hormone regulatory patterns of inorganic pyrophosphatase (PPiase) of male Rhode Island Red (RIR) chickens were studied at two different postnatal ages (5- and 90-day). The endogenous activity level was found to be significantly higher in the immature (5-day) groups for all the tissues (liver, kidney and brain) studied as compared to that of mature (90-day). Hydrocortisone (HC) administration significantly inhibited the PPiase activity in the immature chicken liver and did not affect the enzyme in kidney and brain at either age. In contrast, insulin increased significantly the activity of PPiase in the liver of immature chicken. Kidney PPiase, however, was unaffected to insulin treatment at immature age, while it showed increased activity in mature group. On the other hand, brain PPiase activity was significantly increased at both the ages studied. These findings indicate an age- and tissue-specific regulation of PPiase activity by hydrocortisone and insulin in chicken.