DISTRIBUTION OF SOMATOSTATIN RECEPTOR TYPE 3 IN THE RAT: IMMUNOHISTOCHEMICAL STUDY

Somatostatin receptor type 3 (SSTR-3) was identified immunohistochemically in the rat tissues using specific anti-SSTR-3 serum which was raised in New Zealand white rabbits immunized with a conjugate of synthetic SSTR-3 peptide (28-41) with bovine serum albumin. Immunohistochemical analysis was performed by avidin-biotin complex method. SSTR-3 immunoreactivity was visualized in the central nervous system, anterior pituitary, gastric and duodenal mucosa, Auerbach's and Meissner's nervous branch of gastrointestinal tract, adrenal medulla, testis and pancreas. Significant staining was detected in neural perikarya, axons and dendrites. When using antiserum preincubated with synthetic SSTR-3 peptide (28-41) or rat anterior pituitary homogenate which contains SSTR-3 peptide, no significant stain of the anterior pituitary or neurons in the hypothalamus was detected. These findings suggest that SSTR-3 is widely distributed and that this method is valuable in studying the distribution of SSTR-3 in rats.