RÉSUMÉ
Immobilization stress is thought to increase pro-oxidants that may contribute to the development of lipid peroxidation, atherosclerosis and hypertension. Thus, the present study was designed to investigate the effect of oral administration of selenium [Se] on fasting serum lipids [triglycerides; TG, total cholesterol; TC, low-density lipoproteins; LDL, and Highdensity lipoproteins; HDL] and some hemodynamic [systolic blood pressure; SBP and vascular reactivity of aortic strips to norepinephrine; VRNE] and blood parameters [serum sodium; Na [+] and potassium; K [+]] in rats exposed to immobilization stress. Forty adult male albino rats were used in this study and divided into 5 equal groups [n = 8]; Normal nontreated group [NNT] served as control and given daily distilled water orally for 3 weeks [wks]; Normal Se-treated group [NST] given distilled water for 1 wk, then oral sodium selenite [Se; 1.5 mg/kg] daily for another 2 wks; Immobilized non-treated group [INT] given distilled water for 3 wks, and concomitantly immobilized [6 hs/d for 1 wk] during wk 2; Immobilized Se pre- and concomitant-treated group [ISPC] given Se for 2 wks and concomitantly immobilized during wk 2, then given daily distilled water during wk 3; Immobilized Se concomitant- and post-treated group [ISCP] daily given distilled water for 1 wk, then Se during the last 2 wks with concomitant immobilization during wk 2. INT group showed significant increase of TG, TC, LDL, SBP, VRNE, and Na [+] levels, but significant decrease of HDL and K [+] levels when compared to the corresponding parameters in NNT group. Se supplementation to normal rats did not change significantly any of the tested parameters. On the other hand, ISPC rats revealed significant lower levels of TG, TC, LDL, SBP, VRNE, and Na[+], but significant higher levels of HDL and K[+] when compared to the corresponding parameters in INT group. Moreover, ISCP rats revealed significant lower levels of TG, TC, LDL, SBP, VRNE, and Na[+], but significant higher levels of HDL and K[+] when compared to the corresponding parameters in INT and ISPC groups. From this study, it is concluded that selenium administration in cases of immobilization stress can improve the accompanied state of hyperlipidemia and hypertension specially if supplemented concomitantly and after the immobilization period