LAUSR

In this study, we examined the effect of sodium fluoride (NaF) on oxidative stress in chicken embryonic gonads. Following exposure to varying concentrations of NaF for 6 h, mRNA expression and immunolocalisation of catalase (CAT), sodium dismutase (SOD1 and SOD2) and nuclear respiratory factors (Nrf1 and Nrf) were analysed in the gonads. In the ovary, a dose-dependent increase in mRNA expression of CAT, Nrf1 and Nrf2 following NaF exposure was found, while the intensity of immunolocalised CAT, SOD2 and Nrf1 was higher in NaF-treated groups. In the testis, no effect of NaF on CAT, SOD1 and Nrf1 mRNA levels was observed; however, NaF (3.5-14.2 mM) elevated Nrf2 mRNA expression. NaF, at a dose of 7.1 mM, increased the immunoreactivity of Nrf1 and SOD2. Further experiments evaluated the ovary and testes when incubated with NaF (7.1 mM), vitamin C (Vitamin C, 4 mM) or NaF + Vitamin C. mRNA expression of all four examined genes in the whole ovary and immunoreactivity of Nrf1 and CAT in the ovarian medulla increased in each experimental group. Similar effects were observed in the testis, where mRNA expression, as well as CAT and Nrf2 immunoreactivity, increased in Vitamin C and NaF + Vitamin C-treated groups. In summary, NaF exposure generated oxidative stress which is manifested by increased expression of free radical scavenging enzymes in chicken embryonic gonads. High doses of Vitamin C did not reverse this effect.