Cyclic AMP-mediated jejunal secretion in lactose-fed malnourished rats.

We evaluated the effects of a hyperosmolar lactose load on the functional properties of the jejunal mucosa of protein-energy malnourished rats. Malnourished animals exposed to an oral lactose load showed an enhanced loss of DNA, protein, and sodium into the intestinal lumen as compared to well nourished controls exposed to the same lactose load. Only the jejunum of lactose-fed malnourished rats showed increased levels of 3'-5' cyclic adenosine monophosphate (cAMP), that appeared principally due to an enhancement of adenyl cyclase. Overall, our data strongly suggest that the intestinal mucosa in malnutrition is more sensitive and responds to an osmotic stress by enhanced secretion.