Immunocytochemical and biochemical characterization of angiotensin I and II in cultured neuronal and glial cells from rat brain.
Neuronal and glial cells cultured from neonatal rat brains showed staining for both angiotensin I and II using the peroxidase-antiperoxidase method. In glial cell extracts of normotensive Wistar-Kyoto rats, the concentrations of angiotensin I and II were 12.47 +/- 2.71 (n = 4) and 66.73 +/- 13.28 fmol/mg protein (n = 4). Angiotensin I and II found in neuronal cell extracts of normotensive Wistar-Kyoto rats were 11.29 +/- 2.99 (n = 4) and 60.25 +/- 12.77 fmol/mg protein (n = 4). No significant difference was found in the concentration of angiotensin I and II in both cell types from the same rat strain. Angiotensin I concentrations of 16.83 +/- 3.43 fmol/mg protein (n = 5) determined in neuronal cell extracts derived from spontaneously hypertensive rats did not differ significantly from those found in neuronal cell extracts of Wistar-Kyoto rats. However, neuronal cell extracts from spontaneously hypertensive rats revealed values of 25.19 +/- 4.31 fmol angiotensin II/mg protein (n = 4). This was significantly different (p less than 0.05) and represented a 58% reduction in the angiotensin II levels in neuronal cells from spontaneously hypertensive rats compared to Wistar-Kyoto rat cultures. Angiotensin I and II measured in the growth medium containing 10% plasma-derived horse serum was below the detection limit of both radioimmunoassays. No difference in the angiotensin I and II levels was found in cells kept in serum-free medium. The angiotensin I and II immunoreactive material determined in the cell extracts could be characterized on reversed-phase high pressure liquid chromatography as (Ile5)-angiotensin I and II. (Ile5)-angiotensin III was not detectable.
Hermann
K
K
Department of Physiology, College of Medicine, University of Florida, Gainesville.
Raizada
M K
MK
Sumners
C
C
Phillips
M I
MI
D000803:Angiotensin I / Q000032:analysis*; D000804:Angiotensin II / Q000032:analysis*; D000818:Animals; D001933:Brain Stem / Q000032:analysis* / Q000166:cytology; D002478:Cells, Cultured; D007031:Hypothalamus / Q000032:analysis* / Q000166:cytology; D007150:Immunohistochemistry; D009457:Neuroglia / Q000032:analysis*; D009474:Neurons / Q000032:analysis; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains
D000804:Angiotensin II; D000803:Angiotensin I