Our recent data showed that mRNA expression of hypoxia inducible factor 1 alpha (HIF-1α) in brain blood vessels (BBV) depends on the level of superoxide and suggested that COX-2 can be interrelated with HIF-1α (1). This study aimed to assess the effects of HS and a superoxide scavenger TEMPOL (T) on expression of antioxidative genes (Cu/ZnSOD, MnSOD, EC-SOD, catalase (CAT) and glutathione-peroxidase 1 and 4 (GPx1 and GPx4)) in regard to HIF-1α expression and their interrelation to each others in microcirculation. Four groups of 11-weeks old healthy male Sprague-Dawley rats were included in the study: low salt group (LS; standard rat chow (0.4% NaCl) and HS group (4% NaCl in chow) for 1 week with or without TEMPOL in vivo (drinking water, 1nM/L) (LS+T and HS+T). Following diet protocol, rats were anesthetized with ketamine (75 mg/kg) and midazolam (2.5 mg/kg) decapitated and their BBV were harvested. mRNA levels were determined by real-time qPCR. Data were analyzed by One-way ANOVA (SigmaPlot 11.0) and MANOVA test (IBM SPSS Statistics 20). p<0.05 was considered significant. All experimental procedures conformed to the European Guidelines (Directive 86/609) and were approved by the local Ethical Committee (Class:602-04/14-08/06, #2158-61-07-14-04) Expression of MnSOD and CAT was significantly increased in LS+T group compared to other groups (p<0.05). Cu/Zn SOD, EC-SOD and GPx4 expression was decreased in HS and LS groups compared to LS+T group and Cu/Zn SOD, EC-SOD, GPx4 expression were decreased in HS group compared to HS+T and to LS+T (<0.001). EC-SOD expression was decreased in LS group compared to HS+T group (p<0.05). GPx1 expression increased in LS and HS compared to HS+T (p<0.001, p=0.002 respectively). Expression of HIF-1α was significantly increased in both T groups compared to both, LS and HS group (LS vs. LS+T p=0.005; LS vs. HS+T p=0.042; HS vs. LS+T p<0.001; HS vs. HS+T p=0.003). Correlations of HIF-1α with antioxidative genes were found only in HS and HS-T groups. In HS group, HIF-1α positively correlated with MnSOD (r=0.935, p=0.002) and GPx1 (r=0.834, p=0.02) and in HS+T group with CAT (r=0.925, p=0.024). Positive correlation of HIF-1α gene expression with the antioxidative enzymes in HS groups suggests that a longer period of NaCl intake could significantly modify its expression. The expression of HIF-1α gene depends largely on expression of MnSOD (2). Since the expression of MnSOD did not significantly change compared in HS diet to LS diet, it is possible that this is additional reason for unchanged HIF-1α expression. Increased expression of HIF-1α in TEMPOL, together with increased MnSOD expression suggest that HIF-1α expression depends on other antioxidant genes’ expression and the level of oxidative stress.