RATS SUBJECTED TO A LOW CONCENTRATION OF CIGARETTE-SMOKE HAVE ELEVATED PLASMA 2,5-DIHYDROXY-BENZOIC ACID CONCENTRATIONS - EFFECT OF ANTIOXIDANT VITAMIN SUPPLEMENTATION

Cigarette smoke, regarded as an independent risk factor for ischaemic heart disease, contains numerous radicals. The aim of this study was t o assess the hydroxyl radical, measured as 2,3- and 2,5-dihydroxy-benz oic acid (DHBA), production rate in different organs and plasma as wel l as the concentration excreted in the urine, due to exposure to smoke . The effect of antioxidant vitamin supplementation was also investiga ted. An increased urinary concentration of 2,5-DHBA, but not 2,3-DHBA during the first few weeks of smoke exposure occurred in the groups ex posed to cigarette smoke and supplemented with antioxidant vitamins. E xposure to smoke alone did not alter 2,3- or 2,5-DHBA urinary excretio n, but significantly increased the 2,5-dihydroxy-benzoic-acid concentr ation in plasma, and antioxidant vitamin supplementation did not alter this elevation. Hydroxyl radical production could, therefore, not be demonstrated, but cytochrome P450 dependent reactions might be involve d.