Inhibition of intestinal glucose absorption in rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin.
Male Sprague-Dawley rats were injected with either 125 micrograms 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)/kg or vehicle (pair-fed and ad libitum-fed controls). Transfer of water, electrolytes and D-glucose as well as fats of a tracer dose of the non-metabolizable radioactive marker 3-O-methyl-D-[U-14C]glucose was studied in isolated perfused jejunal segments 1, 2, 7, and 21 d after treatment (TCDD-treated and pair-fed control rats) and after 26 d in ad libitum-fed controls. TCDD-treated rats demonstrated reduced feed consumption and loss of body weight. Active intestinal absorption of glucose was significantly inhibited 30 and 22% compared to pair-fed controls, respectively 2 and 7 d after TCDD treatment. After 21 d the inhibition (14%) was less significant. There were no differences in glucose transfer between severely starved pair-fed controls (body weights 370 +/- 26 g) and ad libitum-fed rats (body weights 512 +/- 15 g). Water absorption and transfer of sodium and calcium was not influenced by TCDD treatment. However, a significant increase of potassium transfer was observed in parallel with impaired glucose absorption. The uptake of 3-O-methylglucose into mucosal tissue was not impaired, whereas the transfer to the serosal side was significantly inhibited by 30-60% compared to pair-fed as well as ad libitum-fed animals from day 2 until the end of the experiment. These results suggest that TCDD is involved in an inhibition of glucose transport at the basolateral membrane.
Richter
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E
Walther Straub-Institut fur Pharmakologie und Toxikologie, Ludwig-Maximilians-Universitaet Muenchen, Germany.
Hunder
G
G
Forth
W
W
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005947:Glucose / Q000493:pharmacokinetics*; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014882:Water-Electrolyte Balance / Q000187:drug effects; D015431:Weight Loss / Q000187:drug effects
D000072317:Polychlorinated Dibenzodioxins; D005947:Glucose; D011188:Potassium