Schäfer J, Meyerhof W
Department of Molecular Genetics, German Institute of Human Nutrition and University of Potsdam, Potsdam-Rehbrücke, Germany.
Neuropeptides. 1999 Dec;33(6):457-63. doi: 10.1054/npep.1999.0762.
The inhibitory peptide hormone somatostatin and its receptors (sst1-sst5) regulate many physiological functions in the gastrointestinal tract. In an attempt to correlate the various effects of somatostatin in gastrointestinal physiology to individual sst subtypes sst1-sst5, mRNAs have been localized by semiquantitative reverse transcription polymerase chain reaction amplification and in situ hybridization of sst1 and sst3 in the rat alimentary tract. sst1-sst4 mRNAs were found throughout the gastrointestinal tract, sst1 mRNA being more abundant than sst2 and much more abundant than sst3 and sst4 mRNAs. sst5 transcripts were at the detection threshold. sst1 and sst3 mRNAs are present in enterocytes and enteric neurons suggesting a role of these subtypes in the somatostatin-mediated inhibition of acetylcholine release from myenteric neurons and of secretomotor neuron activity in the submucous plexus. The presence of sst3 mRNA in smooth muscle cells points to an additional role of this receptor in regulating gut motility.
抑制性肽类激素生长抑素及其受体（sst1 - sst5）调节胃肠道的多种生理功能。为了将生长抑素在胃肠道生理学中的各种效应与个体sst亚型sst1 - sst5联系起来，通过半定量逆转录聚合酶链反应扩增以及大鼠消化道中sst1和sst3的原位杂交对mRNA进行了定位。在整个胃肠道中均发现了sst1 - sst4 mRNA，其中sst1 mRNA比sst2丰富得多，比sst3和sst4 mRNA丰富得多。sst5转录本处于检测阈值水平。sst1和sst3 mRNA存在于肠上皮细胞和肠神经元中，提示这些亚型在生长抑素介导的抑制肌间神经元乙酰胆碱释放以及黏膜下丛中分泌运动神经元活性方面发挥作用。平滑肌细胞中sst3 mRNA的存在表明该受体在调节肠道运动方面还有额外作用。
