Changes in the activity of Cu/Zn superoxide dismutase, lipid profile and aorta morphology of spontaneously hypertensive rats on zinc diet.

UNLABELLED: The aim of the present study was to investigate the effect of zinc on the activity of copper-zinc superoxide dismutase (Cu/Zn SOD), the lipid profile, the arterial blood pressure and the morphological changes of the aorta in male spontaneously hypertensive rats (SHR). MATERIALS AND METHODS: The study included 52 male SHR animals. The animals were randomly asigned into three groups to be fed one of three zink diets--in group one animals (G1, control group) the zinc content was 50 mg/kg, in group two (G2)--155 mg/kg and in group three (G3) 250 mg/kg. The laboratory chow zinc content and the zinc and copper serum levels were measured by a direct flame atomic-absorption spectrophotometry. The Cu/Zn SOD activity was measured in the erythrocytes using a reagent from RANSOD (RANDOX Laboratories). Systolic arterial blood pressure was measured on the rat's tail (tail cuff) by an indirect method without anesthesia (Ugo Basile). The lipid profile was determined with ABX reagents (France). Histological investigations of the aortas were performed using histochemical and electron microscopic methods. RESULTS: Statistically significant increase of Cu/Zn SOD activity (p < 0.05) was found in G2 (2276.88 +/- 145.53) and G3 (2337.31 +/- 146.25) in comparison with the control group of animals (2099.46 +/- 111.73). There was significant decrease of serum LDL levels (p < 0.05) in G3 (1.09 +/- 0.32) compared with G2 (1.19 +/- 0.42) and G1 (1.62 +/- 0.28). Increased number of migrated smooth muscle cells was found in G1 animals. Lipid drops were increased in the aortic wall of SHR animals and then decreased after zinc diet was applied. CONCLUSIONS: The results indicate that high zinc content in the diet has a protective effect as it increases Cu/Zn SOD activity, decreases the LDL serum levels and the lipid infiltration of the aorta in male SHR animals.

Effect of zinc on the activity of Cu/Zn superoxide dismutase and lipid profile in Wistar rats.

AIM: The aim of the present study was to analyze the effect of zinc on the activity of Cu/ZnSOD, lipid profile and arterial blood pressure in male Wistar rats. MATERIAL AND METHODS: The study included 53 male Wistar rats with basal weight 190-210 g. The animals were divided into three groups and put on diets with different zinc content. Group I animals (G1, n = 18) were on a diet with zinc content 52 mg/kg, group II animals (G2, n = 18) were on a diet with zinc content 155 mg/kg corresponding to standard food and group III animals (G3, n = 17) received zinc supplementation (236 mg/kg diet). The activity of Cu/ZnSOD was measured in erythrocytes with RANSOD reactive (RANDOX). Zinc content in the laboratory chow and serum concentration of zinc and copper were analyzed by direct flame atomic-absorption spectrophotometry. Lipid profile was determined with reactives of ABX (France). Arterial blood pressure was measured on the rat's tail by an indirect method without anesthesia. RESULTS: Statistically significant decrease (p < 0.05) was found in the activity of Cu/ZnSOD in G1 animals (1993.51 +/- 303.01) compared with G2 animals (2307.07 +/- 240.23). There was a statistically significant increase (p < 0.05) of serum LDL in G3 (1.52 +/- 0.21) compared with G1 animals (1.09 +/- 0.27) and statistically significant increase in the serum triglycerides in G1 animals (1.19 +/- 0.22) compared with G3 animals (0.75 +/- 0.17). CONCLUSIONS: The results indicate that the activity of Cu/ZnSOD changes in relation to zinc diet and this correlates with the change in the arterial blood pressure. Lipid variables also are influenced and zinc supplementation leads to increase in the serum LDL and decrease in the serum triglycerides in Wistar rats.