It has become increasingly evident that both quantity and quality of dietary lipid can influence the developmental course of several major forms of @entity5 in experimental animals. Using the hairless @entity19 -ultraviolet (UV) model, we had previously demonstrated that unsaturated lipid compared to equivalent levels of hydrogenated lipid enhanced photocarcinogenesis with respect to both @entity5 latency and multiplicity. In the present study using the same model, we have examined the effect of unsaturated lipid level and antioxidants upon epidermal lipid peroxidation and UV @entity105 . Sixteen groups of 45 animals each were used in the study, representing all combinations of three design variables: (a) a semipurified diet containing 4, 2, or 0.75% @entity4336 oil or 4% @entity1460 oil; (b) 2% (w/w) antioxidant supplement or no supplementation; and (c) an escalating regimen of UV radiation to a cumulative dose of 70 J/cm2 or no irradiation. The nonirradiated groups served as nutritional controls and as subjects for epidermal lipid peroxidation measurements. An approximate linear relationship between lipid level and @entity5 latency was observed, with 4% levels of unsaturated lipid producing maximum enhancement of photocarcinogenesis. Furthermore with increasing lipid level the numbers of @entity5 per animal increased. Antioxidants caused significant increases in @entity5 latency and decreases in @entity5 multiplicity but only at the highest lipid level used in these studies. @entity4466 values of epidermal homogenates also increased in relation to the level of dietary lipid intake. Epidermal @entity4466 values from antioxidant supplemented animals were significantly lower regardless of lipid intake levels. From these data we conclude that (a) dietary lipid level has a direct effect upon the carcinogenic response to UV both in regard to @entity5 latency and @entity5 multiplicity; (b) antioxidants produce an inhibitory effect almost equal to the degree of exacerbation of @entity105 evoked by increasing lipid levels, at least for the range studied; and (c) dietarily administered antioxidants inhibit the formation of epidermal @entity4466 reacting materials. These data strongly imply that free radical reactions, specifically lipid peroxidation, play a role in at least a part of the photocarcinogenic response.

Relation of antioxidants and level of dietary lipid to epidermal lipid peroxidation and ultraviolet XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'cancer', 'tumors'] @entity19 :: ('10090', 'Species') :: ['mouse'] @entity4336 :: ('381124', 'Species') :: ['corn'] @entity4466 :: ('MESH:C029684', 'Chemical') :: ['thiobarbituric acid', 'Thiobarbituric acid'] @entity1460 :: ('3847', 'Species') :: ['soybean'] @entity105 :: ('MESH:D063646', 'Disease') :: ['carcinogenesis']
@entity105 :: (MESH:D063646,Disease) :: ['carcinogenesis']
