Distribution of somatostatin receptor messenger RNAs in the rat gastrointestinal tract.
OBJECTIVE
The gastrointestinal (GI) tract is a major source and target of somatostatin (SRIF). Recently, five pharmacologically different SRIF receptors (sst1-5) were cloned. The cellular and tissue distribution of the sst1-5 messenger RNAs (mRNAs) were studied in the rat GI tract using in situ hybridization histochemistry (ISHH).


METHODS
Two sets of (35)S-uridine triphosphate (UTP)-labeled antisense and sense riboprobes were prepared for each sst. ISHH was conducted on frozen tissue samples from rat stomach, duodenum, jejunum, ileum, colon, and pancreas.


RESULTS
mRNAs of all five sst-s are widely expressed in the rat GI tract. The distribution pattern for each sst mRNA was identical with both antisense probes. No specific signal was found with any of the sense probes. Each layer of the different parts of the gut expressed mRNAs of multiple sst subtypes. All organs expressed sst3 mRNA very intensely. The lowest levels of mRNA expression for all five subtypes within the GI tract were found in the pancreas.


CONCLUSIONS
The widespread expression of sst mRNAs suggests a significant role for SRIF in the regulation of GI function.
Krempels
K
K
Clinical Neuroscience Branch, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4090, USA.
Hunyady
B
B
O'Carroll
A M
AM
Mezey
E
E
D000818:Animals; D004064:Digestive System / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017481:Receptors, Somatostatin / Q000378:metabolism*
D012333:RNA, Messenger; D017481:Receptors, Somatostatin