The activities of phosphatases and aminotransferases in the epithelium of the small intestine and caecum of white rock cockerels during starvation.

Alkaline phosphatase (ALP, EC 3.1.3.1), acid phosphatase (ACP, EC 3.1.3.2), aspartate aminotransferase (ASAT, EC 2.6.1.1) and alanine aminotransferase (ALAT, EC 2.6.1.2) were measured in the mucosal homogenates of the duodenum, jejunum and caecum of full-fed (control), starved and refed White Rock Cockerels. Starvation caused a significant (p less than or equal to 0.05) increase in the activity of ACP in all three segments of the intestine. Subsequent re-feeding brought the activity back to the control level. In contrast ALP activity fell in the duodenum during starvation and was partially restored by refeeding. In the jejunum and caecum the ALP activity decreased during starvation and was fully restored by re-feeding only in the caecum. ASAT activity increased (p less than or equal to 0.05) during the entire period of starvation in all three segments. Re-feeding failed to decrease the enzyme activity within 48 hours. Starvation caused a reduction (p less than or equal to 0.05) in the activity of ALAT and re-feeding did not increase the activity in the duodenum and jejunum. The caecum showed no change in the activity during fasting.