Reports of gender-related differences in the activity of enzymes involved in the metabolism of intracellular antioxidants, led us to verify whether the prostaglandin response to tert-butyl hydroperoxide (TBH) differed according to the sex of infants. Segments of human umbilical veins were perfused in the presence or absence of TBH (0.25 mmol/l, and 1.0 mmol/l). Because TBH is quenched in the cell by glutathione peroxidase, total glutathione concentrations and production of glutathione-dependent prostaglandins (PGE2 and PGF2 alpha) as well as membrane-derived eicosanoids (PGI2 and thromboxane) were measured in the eluate. In veins from boys, TBH induced a sustained response for glutathione only, which was increased (p < 0.05). In female-derived tissue, the hydroperoxide induced a different response according to the dose of TBH. At 0.25 mmol/l, a drop (p < 0.005) in PGF2 alpha was associated with a rise (p < 0.001) in thromboxane. At 1.0 mmol/l, TBH had an opposite effect--there was a rise (p < 0.01) in PGE2 and PGI2. The prostaglandin concentration were not proportional to the oxidative stimulus, suggesting a critical level of TBH at which the oxidative state differs in tissues derived from boys or girls.