Cellular localization of soluble and membrane-bound forms of arylsulfatase in rat brain

The cellular localization of the soluble and membrane-bound forms of the enzyme, arylsulfatase (ArS), in rat brain was investigated by measuring their activities in rat striatum after unilateral lesioning with the neurotoxin, kainic acid. Membrane-bound ArS (C form of ArS) activity was found to increase after lesioning and the increase paralleled that of the astroglial marker enzyme, glutamine synthetase. Total soluble ArS (A and B forms of ArS) was shown to decrease on day 2 after the kainic acid injection but rapidly increase thereafter. When the two soluble forms of arylsulfatase were measured separately, the activity associated with the A form was found to initially decrease followed by a rapid increase in activity, whereas the activity of the B form of the enzyme increased over the entire duration of the experiment. These data suggest that the ArS-C and B form of arylsulfatase predominate in proliferating astroglial cells, whereas the A form of arylsulfatase is present both in neuronal cell bodies and astroglia associated with the rat striatum.