title: Distinct topographical localisation of two somatostatin receptor subpopulations in the human cortex.
abstract: The use of two different radioligands, [125I]Leu8, D-Tryp22,Tyr25-somatostatin-28 and the stable somatostatin octapeptide analog [125I]204-090, D-Phe-Cys[125I]Tyr-D-Trp-Lys-Thr-Cys-Thr(ol), allowed to differentiate between two somatostatin receptor subpopulations in the human cortex. In homogenates, octapeptide somatostatin analogs displaced only part of the somatostatin-28 radioligand with high affinity. Autoradiography showed that the receptor subpopulation labelled with [125I]204-090, which we named SS1, was preferentially localized in layers V and VI, whereas the subpopulation having low affinity for somatostatin octapeptides (named SS2), measured with somatostatin-28 radioligand, was concentrated in the superficial cortical layers (I-IV) and particularly enriched in parts of lamina IV.
mesh_terms: D000368:Aged; D001345:Autoradiography; D002540:Cerebral Cortex / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008875:Middle Aged; D015282:Octreotide; D010446:Peptide Fragments / Q000378:metabolism; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D017481:Receptors, Somatostatin; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism; D053561:Somatostatin-28 / Q000031:analogs & derivatives
chemical_list: D008024:Ligands; D010446:Peptide Fragments; D017981:Receptors, Neurotransmitter; D017481:Receptors, Somatostatin; D013004:Somatostatin; D053561:Somatostatin-28; C045259:somatostatin 28, Leu(8)-Trp(22)-iodo-Tyr(25)-; D015282:Octreotide