Astrocytes can protect neurons against oxidative stress and excitability-dependent disorders, such as epilepsy. Valeriana officinalis has been used as anticonvulsant and can exert an antioxidant effect, which may underlie its opposing action against the toxic effects of the pesticide rotenone. We investigated the V. officinalis/rotenone interaction in the cortical spreading depression (CSD), a phenomenon that depends upon brain excitability (in vivo model). In addition, we analyzed the protective action of V. officinalis against the cytotoxic effects of rotenone in cultures of rat C6 glioma cells (in vitro model). For the CSD study, Wistar rats received either V. officinalis (250 mg/kg/day via gavage for 15 days; n = 8) or 10 mg/kg/day rotenone via subcutaneous injections for 7 days (n = 7), or they received both substances (n = 5). Two control groups received either saline (vehicle for V. officinalis; n = 8) or 1% Tween-80 aqueous solution (vehicle for rotenone; n = 9). After treatment, CSD was recorded for 4 h. The rotenone-and V. officinalistreated groups presented, respectively, with lower (2.96 ± 0.14 mm/min), and higher CSD propagation velocity (3.81 ± 0.10 mm/min) when compared with the controls (Tween-80, 3.37 ± 0.06 mm/min and saline, 3.35 ± 0.08 mm/min; p < 0.05). The rotenone plus V. officinalis-treated group displayed a CSD velocity (3.38 ± 0.07 mm/min) that was similar to controls. In line with these results, in vitro experiments on rat glioma C6 cells revealed a protective effect (MTT assay) of V. officinalis against rotenoneinduced cytotoxicity. These results suggest the therapeutic potential of V. officinalis for treating neurological diseases involving redox imbalance and astrocyte dysfunction.

Dihydrotestosterone (DHT) receptor in human foreskin cytosol. Studies in normal subjects and male pseudohermaphrodites (MPH) Defective masculinization may be due to absent binding of androgen to the target organ receptor. Cytosol prepared directly from a fragment of £0-reskin was incubated with 3~-DHT and analysed by polyacrylamide gel electrophoresis. 10 prepubertal subjects, 5 adults, 4 boys with anterior hypospadias and 3 MPH were studied. Two binding peaks were seen. One was displaced by cyproterone acetate and methyltrienolone but not by estradiol, was modified by high ionic strength and correspcnded to the intracellular receptor. The other was the plasma sex binding protein. Receptor binding was similar in newborns, normal boys and anterior hypospadias (230 f.moles/mg cell prot.). Higher values were found in adults (280 f-moles). No receptor was found in familial MPH Type I, and incomplete testicular feminization but was present in mixed gonadal dysgenesis. This method permits a rapid assessment of androgen receptivity.

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