Determination of thiobarbituric acid reactive products formed from deoxyribose in biological samples

Determination of thiobarbituric acid reactive products (TBAR) formed from d eoxyribose by hydroxyl radicals is used to determine scavenging activity of various chemicals. A method for determination of TEAR was modified to allo w determination of TEAR in presence of biological materials by addition of 1% sodium dodecyl sulfate (SDS) to prevent chromogen adsorption by biologic al matrices. This method was tested using brain extracts from nine 7 - 28 y ear old rhesus monkeys. The inhibitory effect of the homogenates was expres sed as mg of protein which inhibited TEAR formation to the same extent as 0 .208 mmoles of sodium salicylate. The homogenates inhibited the formation o f TBAR in linear, concentration dependent fashion. The day-to-day reproduci bility of the method was found to be 9.2% relative S.D. and the salicylate equivalent values ranged from 0.09+/-0.02 to 0.61+/-0.25 mg of protein amon g the six brain areas investigated. The age and sex were not related to the inhibitory activities of brain extracts.