Heterogeneity of Somatostatin-Like Immunoreactivities Extracted from Rat Small Intestine
The small intestines of 5 rats were successfully divided into the epithelial cells and the muscle layer, and substances with somatostatinlike immunoreactivity (SLI) were extracted to investigate the heterogeneity of rat intestinal SLI. Separation of SLI by gel chromatography revealed that there were large differences in the relative amounts of 3.5K SLI and 1.6K SLI between the epithelial cells and the muscle layer. The ratio of 3.5K SLI / (3.5K SLI + 1.6K SLI) was 67.3±4.0% (Mean±SD, 54.2 ― 81.0%) in the epithelial cells and 14.2±2.6% (Mean±SD, 2.8 ― 18.8%) in the muscle layer. By High Performance Liquid Chromatography (HPLC), 3.5K SLI and 1.6K SLI were shown to correspond to somatostatin-28 (SS-28) and somatostatin-14 (SS-14), respectively. Thus it was demonstrated that SS-28 is predominantly distributed in the epithelial cells, and the SS-14 is mainly located in the muscle layer of rat small intestine.