Dosing-time dependent oxidative effects of sodium nitroprusside in brain, kidney, and liver of mice

• SNP administration at 1 or 13 HALO did not affect, irrespective of sampling-time, the mean of MDA status in mouse tissues.
• SNP increased level of MDA status in a dosing-time-dependent manner in mouse brain and kidney.
• Level of liver lipoperoxidation was not changed after 2.5 mg · Kg−1 SNP administration at 1 HALO.
• SNP treatment amplified time-of-day variation of MDA status in brain and kidney, but not in the liver of mouse.

The purpose of this study was to investigate if the oxidative effects of sodium nitroprusside (SNP) are dosing-time dependent. Therefore, the variation of malondialdehyde (MDA) status was assessed after a single i.p. administration of SNP (2.5 mg kg−1 b.w.) or vehicle (9‰ NaCl) to different and comparable groups of mice (n = 48) at two different circadian times (1 and 13 h after light onset [HALO]). Brain, kidney, and liver tissues were excised over 36 h, and their MDA contents were estimated at 0, 1, 3, 6, 9, 12, 24, and 36 h after SNP administration.Resultsindicated mean MDA level was not significantly changed in each investigated tissue compared with the control. In contrast, the mean MDA value varied among organs and was comparable in brain and liver but lower than in kidney. The data show SNP significantly (P < 0.05) increases MDA status in both tissues and exerts time-dependent oxidative effects with the greatest toxicity coinciding with the beginning of the diurnal rest span (local time: 08:00 h, i.e., at 1 HALO).The obtained results reveal SNP-induced oxidative damage (evidenced by MDA accumulation) varies according to both the dosing-time and the target organ.