Fig. 1.

Expression of GLP-1R. A) Total RNA isolated from the mucosa and muscle tissue of mouse colon was reverse transcribed, and cDNA was amplified with specific GLP-1R primers. Total RNA was also isolated from MIN-6 cells and mouse islets. Experiments were done in the presence or absence of reverse transcriptase (RT). B) Total RNA isolated from cultured (first passage) colonic and intestinal muscle cells was reverse transcribed, and cDNA was amplified with specific GLP-1R primers. PCR products with predicted size (346 bp) were obtained in the presence of reverse transcriptase. C) Lysates prepared from isolated colonic muscle cells were homogenized and protein (lane 1: 20 μg; lane 2: 30 μg) in the supernatant was fractionated by SDS-PAGE followed by western blot analysis using GLP-1R antibody. Bands corresponding to GLP-1R (53 kDa) were visualized by chemiluminescence.