Lipid peroxidation in the kidney of rats treated with V and/or Mg in drinking water

Abstract

Spontaneous and stimulated lipid peroxidation (LPO) after vanadate and magnesium treatment was studied in kidney supernatants obtained from outbred 5-month-old, albino male Wistar rats. The 2-month-old animals daily received: group I (control), deionized water to drink; group II, water solution of sodium metavanadate, NaVO(3) (SMV, 0.125 mg V ml(-1)); group III, water solution of magnesium sulfate, MgSO(4) (MS, 0.06 mg Mg ml(-1)); and group IV, water solution of SMV-MS at the same concentrations as in groups II and III for V and Mg, respectively, over a 12-week period. FeSO(4), NaVO(3) and MgSO(4) were selected as agents that may modify LPO process in in vitro conditions. Spontaneous malondialdehyde (MDA) levels in kidney supernatants increased significantly in the rats in groups II and IV, compared with groups I and III; and they were also significantly higher in all the groups of rats compared with the liver supernatants. The total antioxidant status (TAS) in groups II and IV tended to be higher too. Vanadium concentration in the kidney of the rats in groups II and IV increased, whereas the kidney Mg content in groups II, III and IV decreased, compared with levels in the liver. As the two-way ANOVA indicated, the changes in the basal MDA level, TAS and Mg concentration in the liver of rats at combined V and Mg application only resulted from independent action of V. As far as the in vitro results are concerned, in the supernatants obtained from the rats in groups II and IV, a significant increase in MDA level was demonstrated in the presence of 30 microm of exogenous FeSO(4) as well as 30, 100, 200 and 400 microm NaVO(3) and 100, 200, 400, 600, 800 and 1000 microm MgSO(4), compared with groups I and III. The 600, 800 and 1000 microm of exogenous MgSO(4) also significantly elevated MDA production in the supernatants obtained from the rats in group III, compared with spontaneously formed MDA in the same supernatants. The three-way ANOVA showed that the changes in LPO induced by in vitro treatment of kidney supernatants with exogenous Fe or V or Mg (600, 800 and 1000 microm) were a consequence of independent action of those metals and they also resulted from the interactions between exogenous Fe (Fe(exog)) and endogenous V (V(end)) and between V(end) and exogenous V (V(exog)). In conclusion, V (as NaVO(3)) consumed by the rats with drinking water at a dose of 12.9 mg V kg(-1) b.w. per 24 h for 12 weeks increased the basal LPO and markedly enhanced TAS in the renal tissue. Its pro-oxidant potential was also found in in vitro conditions. The Mg dose (6 mg Mg kg(-1) b.w. per 24 h) ingested by the rats together with V (12.7 mg V kg(-1) b.w. per 24 h) neither reduced nor intensified the spontaneous LPO, compared with V-only intoxicated animals; however, the stimulating effect of Mg on LPO was revealed in in vitro conditions.

The Renal Effects of Vanadate Exposure: Potential Biomarkers and Oxidative Stress as a Mechanism of Functional Renal Disorders—Preliminary Studies

“…All details concerning the methodology of determination of LPO and the preparation of kidney homogenates and supernatants for the renal MDA k and TAS k measurements had already been provided [2, 3]. The results of both the OS markers mentioned are expressed as % of control and illustrated in Figure 4(a).…”

“…Its prooxidant action has been demonstrated in in vivo and in vitro conditions [2–7]. It has been shown that the free radical process-lipid peroxidation (LPO), which is a biochemical biomarker of cellular dysfunction and an index of cytotoxicity [8], is enhanced by V in the kidney [3, 8]. It has also been suggested that LPO may be predictive of renal dysfunction [8].…”

Magnesium Can Protect against Vanadium-Induced Lipid Peroxidation in the Hepatic Tissue

“…The daily intake of water and the solutions of SMV, MS, and SMV-MS were measured with a measuring cylinder and the water and fluid intake was expressed as mL/rat/24 h. In turn, the daily intake of V and Mg in the SMV- or/and MS-administered animals was estimated on the basis of the 24 h consumption of the SMV, MS, and SMV-MS solutions and expressed as mg/kg b.wt./24 h. However, the food intake was calculated on the basis of the 24 h consumption of food by the rats from all the groups (the remainder of food together with additional spillage was weighed and subtracted from the whole food that the rats received to eat) and expressed as g/rat/24 h. The V and Mg concentrations in drinking water were selected on the basis of our previous experiments conducted in a rat model [11, 12, 36] and studies of other researchers [37, 38]. The concentration of V was chosen to reveal its prooxidant potential, which was meant to be attenuated by the administration of this element in combination with Mg.…”

“…However, in some conditions Mg may stimulate LPO causing OS. Its ability to elevate LPO has been revealed by us [11, 12] and by some other investigators [27]. …”

“…In certain conditions, it may enhance the generation of oxygen-derived reactive species and stimulate LPO [10]. Its prooxidant properties have been revealed in in vivo and in vitro conditions both by us [11, 12] and by some other researchers [10, 13–21]. On the other hand, antioxidant action of V [22], its insulin-like effects [23], and anticarcinogenic activity [24–26] have also been reported.…”