Biomaterial Database

Measurement of methionine-enkephalin [Arg6,Phe7] in rat brain by specific radioimmunoassay directed at methionine sulphoxide enkephalin[Arg6,Phe7]. 1982

M R Boarder, and A J Lockfeld, and J D Barchas

A specific and sensitive radioimmunoassay procedure for Met-enkephalin[Arg6,Phe7] which allows its measurement in regions of the rat brain is described. The antiserum as raised against the methionine sulphoxide derivative of the peptide, and all samples and standards were oxidized with hydrogen peroxide prior to use in the assay with chloramine T-oxidized 125I-labelled Met(O)-enkephalin[Arg6,Phe7]. The only significant cross-reactivity was 30% with the reduced heptapeptide Met-enkephalin[Arg6,Phe7]. The assay showed less than 0.15% cross-reactivity with fragments of the heptapeptide and with leucine-enkephalin-containing peptides. Acid acetone extraction of rat striatum followed by Sephadex G-50 chromatography and reverse-phase high pressure liquid chromatography showed that essentially all immunoreactivity co-chromatographed with Met-enkephalin[Arg6,Phe7]. This confirmed the specificity of the assay and showed that the striatum does not contain a high concentration of larger molecular weight forms with the heptapeptide at the COOH terminus. Distribution of the heptapeptide followed that of methionine enkephalin, with highest concentrations in the globus pallidus, intermediate levels in caudate-putamen and hypothalamus, and low levels in cortex and cerebellum.

UI	MeSH Term	Description	Entries
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
D003342	Corpus Striatum	Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.	Lenticular Nucleus,Lentiform Nucleus,Lentiform Nuclei,Nucleus Lentiformis,Lentiformis, Nucleus,Nuclei, Lentiform,Nucleus, Lenticular,Nucleus, Lentiform,Striatum, Corpus
D003429	Cross Reactions	Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.	Cross Reaction,Reaction, Cross,Reactions, Cross
D004723	Endorphins	One of the three major groups of endogenous opioid peptides. They are large peptides derived from the PRO-OPIOMELANOCORTIN precursor. The known members of this group are alpha-, beta-, and gamma-endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; OPIOID PEPTIDES is used for the broader group.	Endorphin
D004744	Enkephalin, Methionine	One of the endogenous pentapeptides with morphine-like activity. It differs from LEU-ENKEPHALIN by the amino acid METHIONINE in position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.	Methionine Enkephalin,5-Methionine Enkephalin,Met(5)-Enkephalin,Met-Enkephalin,5 Methionine Enkephalin,Enkephalin, 5-Methionine,Met Enkephalin
D004745	Enkephalins	One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.	Enkephalin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014018	Tissue Distribution	Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.	Distribution, Tissue,Distributions, Tissue,Tissue Distributions
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus