Biochemical and toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in immature male and female chickens

It has been reported that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induce d body wasting in mammals is associated with decreased adipose tissue lipop rotein lipase (LPL) and glucose transporting (GT) activity with differentia l sensitivity between genders. This study extends those findings to chicken s as an avian model. A significant decrease in body weight gain was demonst rated in immature male and female chickens 10 days after treatment with a s ingle intraperitoneal (i.p.) dose of 10 and 100 mug TCDD/kg. Body weight ga in decrease was associated with hepatomegaly and induction of hepatic CYP1A enzymes in both genders. The increase in liver/body weight ratio (48%) and the decreased LPL activity (28%) were significant only in females at 10 mu g TCDD/kg. However, the increase in liver/body weight ratio (31%) and the d ecrease in LPL activity (26%) were significantly demonstrated in males at 1 00 tg TCDD/kg. Levels of GT were significantly decreased in females (46%) a nd in males (48%) following treatment with 10 mug TCDD/kg and 100 mug TCDD/ kg, respectively. Therefore, in chickens, as in mammals, the TCDD-induced b ody wasting is accompanied with decreased LPL activity and decreased GT act ivity and the magnitude of these changes is gender dependent. In contrast t o mammals, this study suggests that female chickens are equally, if not mor e responsive to TCDD toxicity than males. (C) 2001 Elsevier Science Inc. Al l rights reserved.