Constant light influences the circadian oscillations of circulatory lipid peroxidation, antioxidants and some biochemical variables in rats

Abstract

Temporal oscillations of circulatory thiobarbituric acid reactive substances (TBARS), antioxidants such as reduced glutathione (GSH), superoxide dismutase (SOD), and catalase and glucose, cholesterol, total protein and aspartate transaminase (AST) were studied under LD (12:12 h) and constant light (LL) (500 lux) conditions after exposing the animal for 21 days. Advances in the acrophase of GSH, SOD, catalase, glucose, total protein and (AST) rhythms and delays in TBARS and cholesterol were found; amplitude and mesor values of these rhythms were found to be altered during constant light treatment. The above said circadian alterations during LL exposure may be due to (1) formation of photooxidants and stress mediated lipid peroxidation, suppression of melatonin (2) modulation of neuroendocrine and neurotransmitters rhythm (3) suppression of sleep -wake cycle (4) feeding and locomotion rhythm. The exact mechanism still remains to be explored and further research needed.

Constant Light Dysregulates Cochlear Circadian Clock and Exacerbates Noise-Induced Hearing Loss

“…In the cochlea, we observed that PER2 protein was most expressed in the organ of Corti ( Supplementary Figure S1a ), so the presence of circadian PER2 and antioxidant oscillation in OHCs is possible. Additionally, LL decreased amplitudes of cochlear circadian clock gene mRNA expression and increased 4-HNE in OHCs in response to noise, which is in line with a previous publication showing that LL influences the circadian oscillation of antioxidants [ 46 ] and induces oxidative stress [ 47 ]. Although the detailed mechanisms need to be investigated further, it is likely that LL attenuated the amplitude of antioxidant oscillation in OHCs, which resulted in increased noise vulnerability.…”

Effect of Vimliv on lipid profile and histopathology in ethanol-induced hepatotoxicity in albino Wistar rats

“…Increased levels of FFA may be due to lipid breakdown, which can increase the synthesis of other major lipids and activate NADPH-or NADH-dependent microsomal peroxidation. [26] Phospholipids are basic machinery of cell membranes, mainly acting as regulators of membrane-bound enzymes and in membrane transport processes, and thus they are important in determining the pathology of various diseases. The increased PL content in the ethanol control group may be due to the elevated levels of FFA and cholesterol, which can promote the production of PL.…”