Short-term zinc deficiency affects nuclear factor-kappa B nuclear binding activity in rat testes

We reported previously that feeding zinc-deficient diets for 14 d altered t he oxidant defense system in the testes of young male rats and increased le vels of lipid, protein and DNA oxidation in this tissue. In this study, we investigated the early involvement of oxidative stress in zinc deficiency-i nduced testicular pathology. Weanling male rats (17 d old) were given free access to a control (25 mug Zn/g) or a zinc-deficient (0.5 mug Zn/g) diet, or restricted access to the control diet at a level of intake similar to th at of rats fed the 0.5 mug Zn/g diet (restricted group) for 7 d. Rats fed t he low zinc diet were characterized by low testes zinc and alkaline phospha tase activity compared with ad libitum and restricted controls. Testes prot ein and lipid oxidation variables did not differ among the groups. Higher t han normal (P < 0.05) activities of CuZn (CuZnSOD) and Mn (MnSOD) superoxid e dismutases were observed in the low zinc group. Glutathione peroxidase an d glutathione reductase activities did not differ among the groups. Total g lutathione concentrations were lower in the low zinc and restricted groups than in the control group (P < 0.05). The testes nuclear binding activities of two transcription factors sensitive to oxidants [nuclear factor (NF)-ka ppaB and AP-1] were assessed. AP-1 nuclear binding activity did not differ among the groups, but NF-kappaB nuclear binding activity was lower in the l ow zinc group than in the control groups (P < 0.05). We suggest that the re duction in NF-<kappa>B binding reflects an early response to zinc deficienc y-induced oxidative stress.