Changes of diurnal organization of free-radical modification of macromolecules, antioxidant defense in healthy people exposed to prolonged photoperiod

Abstract

Prolonged artificial light period as a consequence of civilisation, as proven, may disturb some physiological circadian patterns. This may be a background for illnesses development. The aim of investigation was to compare daily profiles of free radical oxidation products and antioxidant patterns in people with usual and disturbed sleeping regimen. 41 healthy volunteers were examined. 6 blood samples were taken during 24 h. 24 people had stable sleep regimen from 11.00 p.m. to 7.00 a.m. (group 1); rest went to bed systematically around 2.00-3.00 a.m. at least 3-4 days per week (group 2). Free radical oxidation products (malonyc dialdehyde, products of free radical protein modification) and antioxidants (restored glutathione content, activity of catalase, gluthathio-neperoxidase, glutathione transferase) were measured by standard biochemical methods. All results were approved statistically. Maximal values of free radical oxidation metabolytes were inverse to antioxidant activity profiles in both groups. But, we established that daily profiles of all investigated parameters were violated in people with late falling asleep. They had lower daily average levels of antioxidants and higher - of products of macromolecules' free radical modification. In addition, shift of acrophase of free radical oxidation.