Brain somatostatin receptors are up-regulated in somatostatin-deficient mice.
The peptide somatostatin (SST) is widely synthesized in the brain and periphery and acts through a family of five receptors (SSTR1-5) to exert numerous effects. A gene product related to SST, cortistatin (CST), also interacts with SSTR1-5. Here we have investigated the regulation of SSTR1-5 and of CST in SST knockout (SSTKO) mice. The five SSTRs were quantitated individually by subtype-selective binding analysis, by immunocytochemistry, and by mRNA measurement and showed, in the brain of SSTKO mice, up-regulation of subtypes 1, 2, 4, and 5, and down-regulation of SSTR3. Peripheral tissues displayed both subtype- and tissue-specific changes in SSTR1-5 mRNA levels of expression. Lack of SST did not up-regulate normal CST expression in brain nor did it induce its expression in the periphery. SST-like immunoreactivity, however, was induced in the proximal midgut in SSTKO animals, suggesting intestinal expression of a novel SST-like gene.
Ramírez
José L
JL
Fraser Laboratories, Department of Medicine, McGill University and Royal Victoria Hospital, Montréal, Québec, Canada, H3A 1A1.
Mouchantaf
Rania
R
Kumar
Ujendra
U
Otero Corchon
Veronica
V
Rubinstein
Marcelo
M
Low
Malcolm J
MJ
Patel
Yogesh C
YC
D000818:Animals; D001921:Brain / Q000378:metabolism*; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017481:Receptors, Somatostatin / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D013004:Somatostatin / Q000172:deficiency* / Q000235:genetics; D014018:Tissue Distribution; D015854:Up-Regulation
D008565:Membrane Proteins; D009479:Neuropeptides; D012333:RNA, Messenger; D017481:Receptors, Somatostatin; C099323:cortistatin; C103631:somatostatin receptor 3; C098681:somatostatin receptor subtype-4; D013004:Somatostatin; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2