Localization of somatostatin mRNA in the gut, pancreas and thyroid gland of the rat using antisense RNA probes for in situ hybridization.

A method for the localization of rat pre-prosomatostatin mRNA by in situ hybridization with 32P- and 3H-labeled antisense RNA probes is reported. Somatostatin mRNA was detected in endocrine cells of the rat gut mucosa, pancreas and thyroid in a distribution identical to immunoreactive somatostatin. In addition, in situ hybridization allowed localization of reactive neurons in the submucous and myenteric plexus of the gut, sites which are variably positive or negative for immunoreactive somatostatin even after colchicine treatment. These studies indicate that in situ hybridization is more sensitive than immunohistochemistry in some instances for demonstration of somatostatin in gene expression.