Journal of Neuroscience, Vol 4, 1598-1606, Copyright © 1984 by Society for Neuroscience
Combination of immunocytochemistry and radioligand receptor assay to identify beta-adrenergic receptor subtypes on astroglia in vitro
PA Trimmer, T Evans, MM Smith, TK Harden and KD McCarthy
There is an increasing need to assess the distribution of receptors for
neuroactive substances on specific neural cell types. This study describes
the establishment of methodology that combines the quantification of
beta-adrenergic receptor subtypes by radioligand binding assays with
immunocytochemical analysis of the contribution of astroglia (identified by
the presence of glial fibrillary acidic protein) and fibroblasts
(identified by the presence of fibronectin) to cultures prepared from
neonatal rat cerebral cortex. The effects of subtle changes in culture
methodology on the cellular composition of cerebral cortical cultures and
the distribution of beta-adrenergic receptor subtypes were examined. The
data indicate that (1) a decrease in the density of the initial plating
suspension, (2) an increase in the age of the animals, or (3)
supplementation of the cortical cell suspension with meningeal fibroblasts
all result in an increase in fibronectin staining and a decrease in glial
fibrillary acidic protein antibody staining. This change in the cellular
composition of the cortical cultures correlated with an increase in the
number of beta 2- adrenergic receptors and a corresponding decrease in the
number of beta 1-adrenergic receptors. These observations point out the
care which must be exercised when preparing primary astroglial cultures of
sufficient purity for large-scale biochemical and pharmacological studies.