MOLECULAR STUDIES OF THE OPIATE RECEPTOR

Project: Research project

Project Details

Description

The goal of the proposed research is the characterization of the Mu, Delta,
and K opiate receptors of the brain and the elucidation of the molecular
mechanism 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 peptides, possible
neurotransmitters or hormones involved in pain perception. Purification of
these receptors 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 subtype size, subunit composition,
conformation, and mechanism of action. Standard hybridization methods will
be used in an attempt to isolate monoclonal antibodies directed against the
Mu, Delta and K receptors of the brain. The monoclonal antibodies will be
used 1) for further purification of the brain 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 K 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 K
opiate receptors. The appearance of Mu and K receptor sites in the
developing animal will be determined and correlated with the ontogenetic
patterns for Mu and K-opiate induced analgesia. The goal of our fourth
project is the purification and identification of an endogenous ligand for
the phencyclidine/Sigma receptors. 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. Such an
understanding of narcotic action should expedite the design of therapeutic
agents which are strong analgesics but do not produce dependence, and
facilitate the production and use of agents of value in the therapy of
patients dependent upon narcotic drugs.
StatusFinished
Effective start/end date12/1/7811/30/87

ASJC

  • Medicine(all)