Immunocytochemically defined astroglia from fetal, newborn and young adult rats express beta-adrenergic receptors in vitro.

Autoradiography of radioligand binding was used to assess the expression of beta-adrenergic receptors (beta-AR) by immunocytochemically identified astroglia cultured from the cerebral cortices of rats 16 days in gestation through 28 days postnatal (DPN). Polygonal astroglia isolated from animals at each age examined were found to exhibit large numbers of beta-AR. In contrast, only low levels of beta-AR could be detected on process-bearing astroglia and fibroblasts. Quantitative analysis showed that there was an increase in the density of beta-AR on polygonal astroglia between 16 days in gestation and 1 DPN. This increase in beta-AR receptor density was present whether the cells were grown for long periods of time in culture (8-22 days) or for short periods of time in culture (1-5 days). The results also suggest that differences in the level of receptor expression between cells grown in short-term and long-term culture may be due in part to culture methodology.