Since the gut responds rapidly to food intake, the levels of expression of several immediate early genes were measured in mucosa from small and large intestine of rats starved for 3 days or refed. Within 1 h of refeeding, jejunal and ileal c-fos, jun B and zif/268 mRNA and colonil zif/268 dramatically increased. The zif/268 gene in jejunum corresponded in size to the full-length cDNA but. in ileum, an RNA band of about 1.2 kb in size increased greatly after feeding. This represents a physiologic in vivo model for the study of gene regulation associated with intestinal epithelial cellular responses to feeding.
