Project: Research project

Project Details


The goal of the proposed research is the characterization of mu, delta, and
kappa opiate receptors and the elucidation of the molecular mechanisms of
opiate action. Opiate receptors are membrane-associated proteinaceous
structures present in mammalian nervous tissue which provide the sites of
action for opiates and endogenous opioid peptides. Purification of these
receptors from brain and from neurotumor cell lines will involve affinity
chromatography, ion-exchange chromatography, HPLC and immunoaffinity
chromatography. Characterization of the solubilized receptors will
emphasize the structural features of the opiate binding sites, receptor
size, protein conformation, amino acid sequence, and mechanism of action.
Standard hybridization methods will be used in an attempt to isolate
monoclonal antibodies directed against brain and neuroblastoma mu, delta,
and kappa receptors. The monoclonal antibodies will be used 1) for further
purification of these opiate receptors, 2) for the elucidation of the
molecular basis of the receptor subtype heterogeneity, and 3) ultimately to
search for the genes encoding the opiate receptors. The uniqueness of our
approach involves our mu receptor preparation, which has been purified
500-fold. The goal of our second project is the elucidation of the
neuroanatomical patterns of kappa and sigma receptors using light
microscopy autoradiography. Visualization of these receptors will be
carried out a) in the presence of mu and delta blocking ligands, or b)
after selective protection of these sites during beta-CNA inactivation.
The goal of a third project is to determine the functional role of mu and
kappa opiate receptors. The appearance of mu and kappa receptor sites in
the developing animal will be determined and correlated with the
ontogenetic patterns for mu and kappa-opiate induced analgesia. The goal
of our fourth project is the elucidation of the cellular mechanisms
subserving 1) upregulation of brain opiate receptors following chronic
administration of narcotic antagonists and 2) downregulation of opiate
receptors following long-term administration of enkephalin in tissue
culture. The goal of our fifth project is the purification and
identification of an endogenous ligand for the phencyclidine/sigma
receptor. Brain extracts have been prepared and will be purified by
successive steps involving preparative and analytic-scale HPLC. Such
studies are hoped to contribute significantly to the understanding of how
the brain works with regard to pain perception and endogenous psychosis and
how, on the molecular level, opiates and opioid peptides exert their
physiological effects including tolerance.
Effective start/end date4/1/803/31/90


  • Medicine(all)
  • Cellular and Molecular Neuroscience
  • Structural Biology
  • Biochemistry
  • Biotechnology
  • Pharmacology