Acid-induced COX-2 expression and prostaglandin E2 production via activation of ERK1/2 and p38 MAPK in cultured feline esophageal smooth muscle cells.

Cyclooxygenase (COX)-2 is known to play an important role in inflammatory conditions such as reflux esophagitis resulting from acid reflux. In this study, we tested whether an acidic medium (pH 4.0) induces an increase in COX-2 expression or PGE(2) production, and explored the implication of mitogen-activated protein kinases (MAPKs) activation in these responses in cultured cat esophageal smooth muscle cells.

Sphingosine 1-phosphate-induced signal transduction in cat esophagus smooth muscle cells.

We investigated the mechanism of contraction induced by S1P in esophageal smooth muscle cells. Western blot analysis demonstrated that S1P(1), S1P(2), S1P(3), and S1P(5) receptors existed in the cat esophagus. Only penetration of EDG-5 (S1P(2)) antibody into permeabilized cells inhibited S1P-induced contraction.