Bruno J F, Xu Y, Song J, Berelowitz M
Department of Medicine, State University of New York, Stony Brook 11794.
Endocrinology. 1993 Dec;133(6):2561-7. doi: 10.1210/endo.133.6.8243278.
The tissue distribution of mRNA encoding five somatostatin receptor subtypes, SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5, was determined in adult rat tissues by solution hybridization/nuclease protection analysis using sequence-specific cRNA probes. In the central nervous system, SSTR1 and SSTR2 mRNA were expressed widely, with highest levels in hippocampus, hypothalamus, cortex, and amygdala and expression of both isoforms in cerebellum and spinal cord. Expression of SSTR3 was also widespread, occurring in all brain regions examined, with the highest level of expression in the cerebellum. SSTR4 mRNA was detected in most brain regions, with highest levels occurring in the hippocampus, cortex, and olfactory bulb. No detectable levels were found in cerebellum. SSTR5 showed a unique pattern of expression in the central nervous system, being found primarily in the hypothalamus and preoptic area. In peripheral tissues, high levels of SSTR1 and SSTR2 mRNA were found in pituitary and spleen. SSTR1 mRNA was also found in the heart and intestine, SSTR2 was detected in pancreas, and both isoforms were expressed in stomach. Expression of SSTR3 was noted in heart, liver, stomach, intestine, kidney, spleen, and pituitary. The patterns of expression were similar for SSTR4 and SSTR3 mRNA; however, SSTR4 was not expressed in liver. SSTR5 was expressed predominantly in the pituitary, but detectible levels were observed in spleen and intestine. Thus, the SSTR subtype mRNA showed both a tissue-specific and overlapping pattern of expression. Taken together with SSTR-specific signal transduction systems, this probably explains the diverse physiological actions of somatostatin.
采用序列特异性cRNA探针，通过溶液杂交/核酸酶保护分析，测定了成年大鼠组织中编码5种生长抑素受体亚型（SSTR1、SSTR2、SSTR3、SSTR4和SSTR5）的mRNA的组织分布。在中枢神经系统中，SSTR1和SSTR2 mRNA广泛表达，在海马体、下丘脑、皮层和杏仁核中水平最高，且在小脑和脊髓中均有这两种亚型的表达。SSTR3的表达也很广泛，在所检测的所有脑区均有表达，在小脑中表达水平最高。在大多数脑区检测到SSTR4 mRNA，在海马体、皮层和嗅球中水平最高。在小脑中未检测到可检测水平。SSTR5在中枢神经系统中呈现独特的表达模式，主要存在于下丘脑和视前区。在周围组织中，垂体和脾脏中发现高水平的SSTR1和SSTR2 mRNA。在心脏和肠道中也发现了SSTR1 mRNA，在胰腺中检测到SSTR2，两种亚型在胃中均有表达。在心脏、肝脏、胃、肠道、肾脏、脾脏和垂体中均注意到SSTR3的表达。SSTR4和SSTR3 mRNA的表达模式相似；然而，SSTR4在肝脏中不表达。SSTR5主要在垂体中表达，但在脾脏和肠道中也观察到可检测水平。因此，SSTR亚型mRNA呈现出组织特异性和重叠的表达模式。结合SSTR特异性信号转导系统，这可能解释了生长抑素多样的生理作用。
