ALTERATION OF LACTASE AND AMINOPEPTIDASE N EXPRESSION IN PORCINE ENTEROCYTES BY ENERGY INTAKE AND ENVIRONMENT

¹ A.F.R.C. Institute of Animal Physiology, Babraham, Cambridge CB2 4AT, England

The influence of nutrition, environmental temperature and time of feeding on lactase and aminopeptidase N activities in enterocytes of young pigs has been investigated. Animals were kept in the cold (10 °C) or warm (35 °C) and given either a high or low energy intake. In animals from the cold, lactase activity as determined by scanning microdensitometry was significantly lower at 4 h after a meal than it was in animals from the warm. At 6 h, the activities were similar in all groups, while at 20-24 h after feeding, lactase activity was much greater in those kept at 10 °C than in those at 35 °C. Level of energy intake had no statistically significant effect and no differences were found with respect to aminopeptidase N. The possibility that these differences in lactase activity are related to thyroid hormone metabolism and energy supply in relation to demand is discussed.