title: Han/Wistar rats are exceptionally resistant to TCDD. I.
abstract: Adult male Han/Wistar rats were administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) intraperitoneally at doses ranging from 125 to 1400 micrograms/kg and monitored for 39 to 48 days. Two rats succumbed in the course of the experiment: one in the group receiving 625 and one dosed 1000 micrograms/kg. Body weights of the animals decreased by 20 to 30% during the first 10 to 14 days and became stable thereafter. Feed consumption decreased to 1/3-1/2 of control levels by Day 4 (calculated per metabolic body mass) and returned gradually to starting values by about 4 weeks after dosing. Water intake displayed a triphasic pattern: at first it was slightly increased (Days 1 to 3), then reduced (on Days 4 to 12) and finally increased again throughout the remainder of the test period. The absolute and/or relative weights of thymus, testicles, ventral prostate and interscapular brown fat were significantly decreased at termination. These results indicate that the LD50-value for TCDD in the male, adult Han/Wistar rat is substantially above 1400 micrograms/kg, and that suppression of appetite is the principal phenomenon responsible for TCDD-induced body weight reduction.
mesh_terms: D002001:Adipose Tissue, Brown / Q000187:drug effects; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003967:Diarrhea / Q000139:chemically induced; D004147:Dioxins / Q000633:toxicity*; D004326:Drinking / Q000187:drug effects; D004351:Drug Resistance; D004435:Eating / Q000187:drug effects; D008297:Male; D009929:Organ Size / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains / Q000502:physiology* / Q000652:urine; D013045:Species Specificity
chemical_list: D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins