Biochemical and functional effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the heart of female rats.
Biochemical, functional and morphologic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the hearts of female rats were examined. Six days after the treatment of rats with TCDD, the blood pressures and resting heart rates were significantly less than in control animals. Treated animals were also less responsive to the effects of the beta-1 agonist, (-)isoproterenol. No histopathologic changes were observed in the heart although extensive centrilobular necrosis occurred in the liver after TCDD administration. Serum levels of thyroxine were 66% less than in control animals. Marked lipid peroxidation was produced in the liver with small but significant increases occurring in the heart. TCDD administration had no effect on catalase activity in the heart, but produced a 20% decrease in superoxide dismutase activity relative to control animals. The effects of TCDD on cardiac function do not appear to be due to a direct action of the xenobiotic on the heart but possibly to a down-regulation of beta-receptors in the heart as a result of the hypothyroid state.
Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha 68105.
S J
SJ
Hermansky
T L
TL
Holcslaw
W J
WJ
Murray
R S
RS
Markin
S J
SJ
Stohs
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004147:Dioxins / Q000494:pharmacology*; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology; D008054:Lipid Peroxides / Q000096:biosynthesis; D008099:Liver / Q000187:drug effects / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013963:Thyroid Hormones / Q000097:blood
D004147:Dioxins; D008054:Lipid Peroxides; D000072317:Polychlorinated Dibenzodioxins; D013963:Thyroid Hormones; D005979:Glutathione Peroxidase; D007545:Isoproterenol