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Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on guinea pig heart muscle.
- Source :
-
Toxicology and applied pharmacology [Toxicol Appl Pharmacol] 1987 Jul; Vol. 89 (3), pp. 408-17. - Publication Year :
- 1987
-
Abstract
- Cardiac effects of TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) were examined using atrial muscle isolated from young or mature guinea pigs fed ad libitum, from young animals 10 or 20 days after a single ip injection of 1 microgram TCDD/kg body wt, and from control guinea pigs pair-fed to the TCDD-treated animals. Basal contraction force of left atrial muscle obtained from TCDD-treated and pair-fed control guinea pigs 10 days after treatment was significantly increased compared to atrial muscle obtained from ad libitum control animals. Atrial muscle from TCDD-treated animals 20 days after treatment had a significantly lower basal force of contraction while that from pair-fed animals was significantly higher relative to atrial muscle from ad libitum control animals. These results suggest that the TCDD-induced change in basal atrial contraction force is in part due to undernutrition and that prolonged exposure to TCDD inhibits this response observed in pair-fed animals. Furthermore, prolonged TCDD treatment shifted the dose-response curve for the positive inotropic effect of isoproterenol to the right with no statistically significant change in the maximal inotropic effect obtained with high concentrations of isoproterenol. The TCDD-induced changes in force of contraction and the dose-response curve for the positive inotropic effect of isoproterenol were similar in young TCDD-treated and mature control guinea pigs. TCDD did not alter the basal contraction frequency or the dose-response curve for the positive chronotropic effect of isoproterenol. There was no effect on cardiac lipoprotein lipase activity at 1 microgram/kg, but in animals administered 4 micrograms TCDD/kg activity was reduced. It was concluded that TCDD adversely affects atrial muscle of guinea pig heart.
Details
- Language :
- English
- ISSN :
- 0041-008X
- Volume :
- 89
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Toxicology and applied pharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 3603569
- Full Text :
- https://doi.org/10.1016/0041-008x(87)90160-8