Connexin Isoform Expression in Smooth Muscle Cells and Endothelial Cells of Hamster Cheek Pouch Arterioles and Retractor Feed Arteries

Objective: Gap junction channels formed by connexin (Cx) protein subunits enable cell-to-cell conduction of vasoactive signals. Given the lack of quantitative measurements of Cx expression in microvascular endothelial cells (EC) and smooth muscle cells (SMC), the objective was to determine whether Cx expression differed between EC and SMC of resistance microvessels for which conduction is well-characterized.Methods: Cheek pouch arterioles (CPA) and retractor feed arteries (RFA) were hand-dissected and dissociated to obtain SMC or endothelial tubes. In complementary experiments, small intestine was dissociated to obtain SMC. Following reverse transcription, quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) was performed by using specific primers and fluorescent probes for Cx37, Cx40, and Cx43. Smooth muscle α-actin (SMAA) and platelet endothelial cell adhesion molecule-1 (PECAM-1) served as respective reference genes.Results: Transcript copy numbers were similar for each Cx isoform in EC from CPA ...