Characterization and distribution of angiotensin II binding sites in fetal and neonatal astrocytes from different rat brain regions

Although angiotensin II (Ang II) binding sites have been extensively investigated in brain, revealing the presence of both AT₁ and AT₂ subtypes in various areas, the question as to which cells express AT₁ and AT₂ sites is still open. We report here that primary cultures of astrocytes obtained from various brain regions of fetal (F17) and one-day-old rats express Ang II binding sites belonging only to the AT₁ subtype. The binding sites have the same binding profile in all regions tested; however, much less binding was observed in membranes of astrocytes derived from cortical than from subcortical regions and almost none were found in neonatal cortex. In addition, the dispersion method used at the onset of culture affects the number of binding sites present at the end of the culture period.