des-AA-1,2,5[D-Trp8, IAmp9]somatostatin-14 allows the identification of native rat somatostatin sst1 receptor subtype.
Somatostatin exerts multiple activities by interacting with at least five different receptor subtypes (sst[1-5]). The affinity of des-AA(1,2,5)-[D-Trp8, IAmp9]somatostatin-14 (CH-275) was studied by competition experiments using the non-selective radioligand [125I][Leu8, D-Trp22, Tyr25]somatostatin-28 in areas of the rat brain and pituitary known to express identified receptor subtypes. In the cerebellar nuclei and cerebral cortex, which possess the somatostatin sst1 receptor subtype, CH-275 exhibited a moderate affinity (IC50: 10-50 nM). Conversely, in the hippocampus, immature cerebellum and pituitary which contain different subsets of receptors mRNAs (sst[2-5]), the IC50 values were > 1 microM. These data indicate that CH-275 is an appropriate ligand for the identification of native rat somatostatin sst1 receptor subtype.
Leroux
P
P
European Institute for Peptide Research (IFRMP No. 23), INSERM U413, UA CNRS, University of Rouen, Mont-Saint-Aignan, France. philippe.leroux@univ-rouen.fr
Bucharles
C
C
Bologna
E
E
Vaudry
H
H
D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D008297:Male; D051381:Rats; D017481:Receptors, Somatostatin / Q000378:metabolism*; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000378:metabolism
C110576:CH 275; C110577:CH 288; D017481:Receptors, Somatostatin; C101130:somatostatin receptor type 1; D013004:Somatostatin