Cortistatin radioligand binding in wild-type and somatostatin receptor-deficient mouse brain

Regul Pept. 2005 Jan 15;124(1-3):179-86. doi: 10.1016/j.regpep.2004.07.015.

Abstract

Cortistatin-14 (CST-14) is a recently discovered member of the somatostatin family of neuropeptides. It shares 11 of its 14 amino acids with somatostatin-14 (SRIF-14). In the present study, binding sites for cortistatin-14 in the mouse brain were examined and compared to those for somatostatin using iodinated cortistatin-14 and iodinated somatostatin-14. By in vitro receptor autoradiography, high densities of cortistatin-14 and somatostatin-14 specific binding sites were detected in the cortex, hippocampal formation, basolateral amygdala and medial habenula. Unlabeled 100 nM cortistatin-14 inhibited iodinated somatostatin-14 binding in the hippocampus, but not in the cortex or amygdaloid nuclei. In somatostatin receptor subtype-2 knock-out (KO) mice, autoradiographic iodinated somatostatin-14 binding was observed in the hippocampus and habenula but was removed in the cortex and amygdaloid nuclei, specific iodinated cortistatin-14 binding sites were found in the hippocampus, habenula and throughout the cortex. We conclude that the somatostatin receptor subtype-2 is responsible for somatostatin binding in cortical and amygdaloid regions and that cortistatin predominantly interacts with the same receptors as somatostatin.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Autoradiography
  • Binding, Competitive
  • Brain / cytology
  • Brain / metabolism*
  • Iodine Radioisotopes
  • Ligands
  • Mice
  • Mice, Knockout
  • Neuropeptides / metabolism*
  • Peptides, Cyclic / metabolism*
  • Radioligand Assay
  • Receptors, Somatostatin / deficiency*
  • Receptors, Somatostatin / genetics
  • Receptors, Somatostatin / metabolism*
  • Somatostatin / metabolism
  • Tyrosine / metabolism

Substances

  • Iodine Radioisotopes
  • Ligands
  • Neuropeptides
  • Peptides, Cyclic
  • Receptors, Somatostatin
  • cortistatin 14
  • Tyrosine
  • Somatostatin
  • somatostatin receptor 2