Toluene treatment in vitro and calcium-regulated protein phosphorylation in primary astroglial cell cultures from the rat striatum.
Primary astroglial cell cultures from striata of newborn rats were exposed to toluene in vitro at doses of between 4.7 and 150 μmol/ml. The protein content of the cell cultures, about 1 mg/ml, was not affected by the toluene treatment. Calcium-induced back-phosphorylation was used to detect changes in the phosphorylation state of calcium-regulated glial phosphoproteins. The 11 most back-phosphorylated protein bands were separated by gel electrophoresis and analysed by autoradiography and computer-assisted image analysis. The back-phosphorylation of the 59-kD protein band was increased by 150% at 9.4 μmol/ml toluene, but no further increase was observed with increasing concentrations. This increase is believed to correspond to a toluene-induced decrease in calcium-regulated protein phosphorylation. Furthermore, there was a trend for decreased back-phosphorylation of the 140-kD band and for increased back-phosphorylation of the 110-kD band in response to the higher concentrations of toluene used. The back-phosphorylation of the 42-, 44-, 48-, 51-, 54-, 63-, 74- and >200-kD protein bands showed no dose-related changes in response to the toluene treatment. Taken together, the data indicate that the 59-kD protein in astrocytes from the rat striatum is specifically sensitive to toluene treatment in vitro.
von Euler
G
G
Department of Histology and Neurobiology, Karolinska Institute, Box 60400, S-10401 Stockholm, Sweden.
Hansson
E
E
Fuxe
K
K