The Mechanisms of Action of Interleukin-1 on Rabbit Intestinal Epithelial Cells

Abstract

Interleukin-1 (IL-1) is an inflammatory mediator that increases Cl-secretion in intestinal epithelial cells. To identify the signal transduction pathway(s) involved in IL-1's action, cells were treated with IL-1 and the levels of cyclooxygenase (COX) enzymes, prostaglandin E2(PGE2) and phospholipase A2-activating protein (PLAP), and the activity of phospholipase A2(PLA2) were measured. IL-1 caused concentrationand time-dependent increases in the levels of PLA2activity, and/or in the levels of PLAP, COX-2 and PGE2. The IL-induced increase in PGE2levels was biphasic, with the first peak due to the increase in PLAP levels, and the second peak due to the increase in COX-2 levels. This increase in PGE2levels may provide a mechanism for acute and chronic inflammation in the intestine.