Chronic steroid sulfatase inhibition by (p-O-sulfamoyl)-N-tetradecanoyl tyramine increases dehydroepiandrosterone sulfate in whole brain.

Dehydroepiandrosterone sulfate (DHEAS) is a neurosteroid which functions as a negative allosteric modulator of the GABA(A) receptor-gated chloride channel. Steroid sulfatase inhibitors including (p-O-sulfamoyl)-N-tetradecanoyl tyramine (DU-14), can potentiate the blockade of the amnestic effects of scopolamine by exogenously administered DHEAS. Moreover, when administered over a 15 day period, DU-14 can block scopolamine amnesia without the concurrent administration of DHEAS. Since the enzyme, steroid sulfatase, facilitates the hydrolysis of the sulfate moiety from DHEAS, the intent of this study was to determine whether chronic administration of DU-14 could increase whole brain concentrations of endogenous DHEAS. Rats were administered DU-14 or corn oil vehicle for 15 days. Following the last day the animals were sacrificed and the brains were removed and analyzed for DHEAS content. DU-14 increased the whole brain concentration of DHEAS 77.6%, from 0.65 +/- 0.06 to 1.15 +/- 0.12 microg/g (mean +/- SEM). This result suggests that steroid sulfatase inhibitors may enhance cognitive function following chronic treatment by increasing the concentration of excitatory neurosteroids such as DHEAS in the brain. Steroid sulfatase inhibitors, therefore, may provide a novel mechanism for facilitating central nervous system function.