Advertisement

2,3,7,8-Tetrachlorodibenzo-P-Dioxin-Induced Weight Loss: A Proposed Mechanism

  • Mark D. Seefeld
  • Richard E. Peterson
Part of the Environmental Science Research book series (ESRH, volume 26)

Abstract

TCDD caused a dose-related decrease in body weight, food intake, motor activity and total and resting oxygen consumption in rats. In animals treated with 15 μg/kg, the depression in food intake and oxygen consumption lasted 2 weeks. Thereafter, the rats consummed the appropriate amounts of food and oxygen for their reduced weights. However, in rats treated with 50 μg/kg, food intake was insufficient to maintain weight. The results suggest that TCDD causes weight loss by a decrease in energy intake (as opposed to an increase in energy expenditure). The decrease in intake of energy could be due to mal-absorption of nutrients from the gastrointestinal tract and/or reduced food intake. Of these, reduction in food consumption is considered to be the main factor involved. This is because weight in pair-fed control rats stabilizes at a level only slightly higher than in TCDD- treated animals. To determine if TCDD is altering a regulatory system for body weight (as opposed to a system controlling food intake), rats had their body weights reduced by food restriction prior to TCDD (25 μg/kg). Immediately after TCDD they were given food ad lib and they exhibited hyperphagia and weight gain. Thus, the ability to feed is not directly inhibited by TCDD. We propose that TCDD lowers a regulated level or “set-point” for body weight and that the change in food intake reflects the rat’s effort to reach the new weight level.

Keywords

Food Intake Reduce Food Intake Total Oxygen Consumption TCDD Treatment Rest Oxygen Consumption 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Allen, J.R., Van Miller, J.P., and Norback. D.H. Tissue distribution, excretion and biological effects of [14 C] tetrachlorodibenzo-p- dioxin in rats. Food Cosmet. Toxicol, 13:501–505, 1975.CrossRefGoogle Scholar
  2. Courtney, K.D., Putnam, J.P., and Andrews, J.E. Metabolic studies with TCDD (dioxin) treated rats. Arch. Environ. Contam. Toxicol 7:383–396, 1978.CrossRefGoogle Scholar
  3. Gasiewicz, T.A., Holscher, M.A., and Neal, R.A. The effect of total parenteral nutrition on the toxicity of 2,3,7,8-tetrachlorodi- benzo-p-dioxin in the rat. Toxicol. Appl. Pharmacol 54:469–488,1980.CrossRefGoogle Scholar
  4. Greig, J.B., Jones, G., Butler, W.H., and Barnes, J.M Toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Food Cosmet. Toxicol, 11:585–595, 1973.CrossRefGoogle Scholar
  5. Gupta, B.N., Vos, J.G., Moore, J.A., Zinkl, J.G., and Bullock, B.C. Pathological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in laboratory animals. Environ. Health Perspect, 5:125–140, 1973.CrossRefGoogle Scholar
  6. Harris, M.E., Moore, J.A., Vos, J.G. and Gupta, B.N. General biological effects of TCDD in laboratory, animals. Environ. Health Perspect 5:101–109, 1973CrossRefGoogle Scholar
  7. Kleiber, M. The Fire of Life, New York: R.E. Krieger Co., 1975Google Scholar
  8. Kociba, R.J., Keeler, P.A., Park, C.N., and Gehring, P.J.2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD): Results of a 13- week oral toxicity study in rats. Toxicol. Appl. Pharmacol 35:553–574, 1976.CrossRefGoogle Scholar
  9. McConnell, E.E., Moore, J.A., Haseman, J.K., and Harris, M.W. The comparative toxicity of chlorinated dibenzo-p-dioxins in mice and guinea pigs. Toxicol. Appl. Pharmacol, 44:335–356, 1978a.CrossRefGoogle Scholar
  10. McConnell, E.E., Moore, J.A., and Dalgard, D.W. Tocicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in rhesus monkeys (Macaca mulatta) following a single oral dose. Toxicol. Appl. Pharmacol, 43:175–187, 1978b.CrossRefGoogle Scholar
  11. McConnell, E.E., and Shoaf, C.S. Studies of the mechanism of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity-lipid assimilation. I. Morphology. The Pharmacologist, 23 (3): 342, 1981.Google Scholar
  12. Seefeld, M.D., Albrecht, R.M., and Peterson, R.E. Effects of 2,3,7,8-tetracholorodibenzo-p-dioxin on indocyanine green blood clearance in rhesus monkeys. Toxicol., 14: 263–272, 1979.CrossRefGoogle Scholar
  13. Seefeld, M.D., Albrecht, R.M., Gilchrist, K.W., and Peterson, R.E. Blood clearance tests for detecting 2,3,7,8-tetrachlorodibenzo- p-dioxin hepatotoxicity in rats and rabbits. Arch. Environ. Contam. Toxicol, 9:317–327, 1980.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1983

Authors and Affiliations

  • Mark D. Seefeld
    • 1
  • Richard E. Peterson
    • 1
  1. 1.School of Pharmacy and Environmental CenterUniversity of WisconsinMadisonUSA

Personalised recommendations