Bile duct ligation induced acute inflammation up-regulates cyclooxygenase-2 content and PGE2 release in guinea pig gallbladder smooth muscle cell cultures

Introduction: This study examines hypotheses that BDL induces increased guinea pig gallbladder smooth muscle PGE(2) release by up-regulation of COX-2. Methods: BDL, Sham and Control Hartley guinea pig gallbladders were placed in cell culture, grown to confluence and underwent Western Blot analysis for smooth muscle cell content of COX-1, COX-2, Prostacylin Synthase, actin, caldesmon, vinculin, metavinculin and tropornyosin and were assayed for basal release of 6-keto-PGF(1 alpha), PGE(2) and TxB(2) by EIA. Results: BDL did not alter content of smooth muscle cytoskeletal proteins. BDL for 48 h increased smooth muscle cell release of PGE(2) and 6-keto-PGF(1 alpha) by 3-fold or more when compared to the Control and Sham groups. Western Blot analysis showed increased content of COX-2 in the BDL group. Conclusions: BDL for 48 h markedly increased endogenous guinea pig smooth muscle cell PG release, which was due to increased COX-2 synthesis. (c) 2005 Elsevier Ltd. All rights reserved.