Opiate Receptor Subtypes
Abstract
This report presents a chart which represents an attempt to integrate three schools of thought regarding the biological identities and functions of multiple opiate receptor subtypes. The accuracy of these estimates of functional specifity is only as precise as the ligands employed and may vary according to experimental conditions. At high doses, most of the ligands indicated in the table cross-react with other receptor subtypes. Pasternak and colleagues have suggested that high affinity (mu1) opiate receptors provide a common binding site for alkaloid and peptide opiates, whereas selectively different effects of opiate ligands may be mediated by separate, low affinity sites (e.g. mu2, delta, kappa and epsilon). Pert and colleagues have further identified Type I receptors (high affinity, adenylate cyclase-coupled) which may demonstrate fluctuating affinities and interconvert between Mu and delta conformations. Type II receptors are fixed in a delta conformation pattern. It is possible that Type I receptors are similar to mu1 receptors as listed. It has recently been indicated that mu and delta binding sites may be allosterically coupled or interconvert. Holaday and colleagues have extended the observations to demonstrate functional interactions among kappa, mu, and delta binding sites. The effect of opiates on the immune response is an emerging area of investigation and designation of receptor subtypes mediating these responses is very speculative.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 06, 1985
- Accession Number
- ADA165206
Entities
People
- John W. Holaday
Organizations
- Walter Reed Army Institute of Research