The effects of magnesium - antidepressants co-administration on the spontaneous behavior in old rats

Antidepressant medication is extensively used to treat the affective disorders and to prevent their --norepinephrine reuptake inhibitors are preferred instead of tricyclic antidepressants, due to their good tolerability, cardiovascular safety, low anticholinergic activity. Magnesium is one of the most wide-spread bivalent cation in the environment, being the fourth major element in the body (after sodium, potassium and chloride), and the second most abundant inside the cells. It plays a key role in the body homeostasis, being involved as enzyme co-factor in more than 300 biochemical processes.We aimed to investigate the effects of magnesium associated with sertraline and venlafaxine on the spontaneous motor activity in old rats. Method: The experiment was carried out on white male Wistar old rats (aged 18 months), randomly separated into 6 groups of 7 animals each, treated orally, during 1 month, according to the following protocol: Group I (Control): saline solution 0,3 ml/100 g weight; Group II (Mg): magnesium chloride 1 mmol//kbw; Group III (SRT): sertraline 3 mg/kbw; Group IV (VLX): venlafaxine 8 mg/kbw; Group V (SRT+Mg): sertraline 3 mg/kbw + magnesium chloride 1 mmol//kbw; Group VI (VLX+Mg): venlafaxine 8 mg/kbw + magnesium chloride 1 mmol//kbw. The animal spontaneous behavior and locomotor activity were evaluated using a LE-8811 Actimeter Panlab Apparatus, automatically counting the total movements on a horizontal plane, the escape attempts and the number of stereotype movements, during sessions of 8 minutes interval. All recorded data were expressed as mean +/- standard deviation of mean and were statistically analyzed using SPSS 17.0 for Windows software: the ANOVA method and Newman-Keuls as post-hoc test. The p values below 0.05 were considered to be significant compared to Control group. The study protocol was reviewed and approved by the Ethics Committee on Research of the ‘Grigore T. Popa’ University of Medicine and Pharmacy, Iasi, Romania, in agreement with the international ethical regulations, regarding the care and handling of laboratory animals. Results: Chronic use of 3 mg/kbw sertraline and of 8 mg/kbw venlafaxine produced a statistically significant (p