Autoradiographic analysis of binding sites for 125I-Bolton-Hunter-substance P in the human eye

Peptides. 1990 Jul-Aug;11(4):655-9. doi: 10.1016/0196-9781(90)90175-5.

Abstract

Substance P is known to exert potent effects in peripheral tissues, and is thought to be important for ocular function. The mechanism of action of substance P in the human eye is not known. As a basis for biochemical characterization specific binding of 125I-Bolton-Hunter-substance P was demonstrated in the human eye using autoradiographic methods. Biochemical characterization on slide-mounted tissue preparations showed that binding was saturable with a KD of 0.27 +/- 0.1 nmol/l. Specific binding occurred at comparable autoradiographic densities to both human retina and choroid. Substance P and its carboxyterminal fragment, substance P(3-11), were shown to be highly potent in binding competition experiments against 125I-Bolton-Hunter-substance P. Similar concentrations of substance P(1-9), neurokinin A and neurokinin B failed to significantly alter specific binding of 125I-Bolton-Hunter-substance P. The results indicate expression of high affinity substance P binding sites in human retina and choroid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoradiography
  • Binding, Competitive / physiology
  • Humans
  • Iodine Radioisotopes
  • Radioligand Assay
  • Receptors, Neurokinin-1
  • Receptors, Neurotransmitter / analysis*
  • Retina / metabolism*
  • Substance P / metabolism*
  • Succinimides / metabolism*

Substances

  • Bolton Hunter reagent-substance P conjugate
  • Iodine Radioisotopes
  • Receptors, Neurokinin-1
  • Receptors, Neurotransmitter
  • Succinimides
  • Substance P