Quantitative radioimmunohistochemical method using (/sup 125/I)-protein A to measure the content of methionine enkephalin in discrete rat brain areas
We report a quantitative radioimmunohistochemical method, using (125I)-protein A in combination with a specific antibody to methionine enkephalin (Met-enk), for determination of the content of this peptide in discrete areas of rat brain. After paraformaldehyde fixation, rat brain sections were incubated with a Met-enk polyclonal antibody, followed by incubation with (125I)-protein A. After autoradiography with 3H-sensitive Ultrofilm, optical densities (OD) were quantified by computerized microdensitometry. The OD obtained were compared to a standard curve, constructed after determination by radioimmunoassay of the Met-enk content in corresponding brain areas from adjacent tissue sections. After comparing 15 different brain areas over a ninetyfold range of concentrations, we found a linear relationship between the content of Met-enk, as determined by radioimmunoassay, and the OD generated by autoradiography. The content of Met-enk in other discrete brain areas can be quantified by interpolation of the OD determined by autoradiography in the standard curve. The method allows, for the first time, precise quantification of peptide concentrations in discrete areas and nuclei from thin sections of rat brain. This technique has a more than 100-fold higher sensitivity than classical radioimmunoassays, with the additional advantage of neuroanatomical localization. It also has the potential for application to the quantification of many other antigens present in brain and other tissues.
- Research Organization:
- National Institute of Mental Health, Bethesda, MD (USA)
- OSTI ID:
- 6801247
- Journal Information:
- J. Histochem. Cytochem.; (United States), Vol. 36:11
- Country of Publication:
- United States
- Language:
- English
Similar Records
Radioimmunoassay of met-enkephalin in microdissected areas of paraformaldehyde-fixed rat brain
Quantitative distribution of angiotensin II binding sites in rat brain by autoradiography
Related Subjects
ENKEPHALINS
RADIOIMMUNOASSAY
ANTIBODIES
AUTORADIOGRAPHY
CEREBRAL CORTEX
IODINE 125
METHIONINE
PROTEINS
RATS
SENSITIVITY ANALYSIS
TRITIUM COMPOUNDS
AMINO ACIDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CEREBRUM
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENDORPHINS
IMMUNOASSAY
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIPOTROPIC FACTORS
MAMMALS
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PEPTIDES
POLYPEPTIDES
RADIOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
RODENTS
TRACER TECHNIQUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques