Benzo(a)pyrene enhances atherosclerosis in White Carneau and Show Racer pigeons

Benzo(a)pyrene (BaP), a major environmental pollutant and component of cigarette smoke, is both carcinogenic and atherogenic in experimental models. We investigated the effect of long-term administration of BaP on atherogenesis in both atherosclerosis-susceptible White Carneau (WC) and atherosclerosis-resistant Show Racer (SR) pigeons. The number and size of arterial lesions in the brachiocephalic arteries in WC and SR females but not males were significantly enhanced after long-term dosing with BaP. Metabolic activation appears to be required for BaP atherogenicity, since benzo(e)pyrene (BeP), a noncarcinogenic analogue of BaP, did not enhance lesion development. Studies with 3H-BaP revealed no significant differences between male and female or between WC and SR pigeons in the arterial distribution of BaP and/or its metabolites. There were no consistent differences in blood pressure or plasma cholesterol levels between breeds or sexes. However, chronic administration of BaP did result in complete infertility in female birds, concomitant with grossly visible changes in ovarian appearance. These results clearly show that long-term dosing with BaP alters ovarian structure and function in treated birds, at the same time aggravating the development of arterial lesions. Thus, BaP-induced atherogenicity in female pigeons may be a consequence of an alteration in estrogen production or of antiestrogenic properties of BaP at the level of the arterial wall and may serve as a highly useful animal model to examine the well-known rapid development of atherosclerosis in postmenopausal women.

Accumulation of malondialdehyde in mouse heart following acute dosing with adriamycin is strain specific and unaffected by cardiac catalase status

CDF1 and C57BL/6J male mice were acutely dosed with Adriamycin (ADR), and total cardiac malondialdehyde (MDA) quantitated following isolation by modification of previously developed procedures. Cardiac MDA content in CDF1 mice increased significantly 5 days following ADR dosing as reported by others, but was unchanged in C57BL/6J mice. ADR-induced mortality and a significant loss in cardiac weight 2-3 days after treatment was similar in both strains. Cardiac lipid hydroperoxide (LH) content was also unchanged in C57BL/6J mice dosed acutely with ADR. However, hepatic LH content increased rapidly following treatment with ADR, reaching maximal level 1 day following treatment before returning to below untreated levels 24 hours later. Studies with genetically acatalasemic C57BL/6J mice showed that neither cardiac nor hepatic lipid hydroperoxide content in ADR-dosed animals is affected by tissue catalase levels. These results demonstrate that C57BL/6J mouse heart is refractory to ADR-induced lipid peroxidation (LP) although overall mortality from the drug is unaffected, and do not support the hypothesis that ADR-induced mortality in mice is a consequence of cardiac LP.