The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Role of the aryl hydrocarbon receptor and Cyp1b1 in the antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The role of aryl hydrocarbon receptor (AhR) and cytochrome P450 (Cyp) 1 family in the antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) was investigated in vivo. Immature (21 days old) AhR, Cyp1a2, or Cyp1b1 knockout (-/-) mice were treated intraperitoneally with estradiol (E2, 20 ng/mouse per day, for 14 consecutive days) and/or TCDD (200 ng/mouse per day, on days 7, 9, 11, and 13). Uterine wet weight and uterine peroxidase activity (UPA) were measured as markers of estrogen responsiveness. UPA was a better marker of estrogen responsiveness than the uterine wet weight. In AhR wild-type (+/+) mice, UPA (208.1+/-81.6 units/g tissue) was increased by the administration of E2 (to 297.2+/-178.7 units/g). The administration of TCDD significantly ( p<0.01) decreased the UPA (10.5+/-3.4 units/g) compared with that in the control mice. Co-administration of TCDD with E2 also significantly ( p<0.05) decreased the UPA (18.8+/-19.9 units/g) compared with that in E2-treated mice. In AhR(-/-) mice, UPA (162.9+/-146.7 units/g) was significantly ( p<0.01) increased by the administration of E2 (486.8+/-108.2 units/g). In contrast to the results in AhR(+/+) mice, UPA was not affected by the administration of TCDD (51.8+/-70.6 units/g) compared with control, and co-administration of TCDD with E2 (545.8+/-189.4 units/g) compared with that in E2-treated mice. In Cyp1a2/1b1(+/+) mice, UPA was significantly ( p<0.05) increased by the administration of E2 (70.0+/-36.4 units/g). Co-administration of TCDD with E2 significantly ( p<0.05) decreased the UPA (29.6+/-22.2 units/g) compared with that in E2-treated mice. In Cyp1a2(-/-) mice, co-administration of TCDD with E2 significantly ( p<0.01) decreased the UPA (6.8+/-5.1 units/g) compared with that in E2-treated mice. In Cyp1b1(-/-) mice, UPA (5.5+/-8.1 units/g) was significantly ( p<0.05) increased by the administration of E2 (56.6+/-34.1 units/g). In contrast to the results in Cyp1a2/1b1(+/+) mice or Cyp1a2(-/-) mice, UPA was not affected by the co-administration of TCDD and E2 (52.6+/-30.1 units/g) compared with that in E2-treated mice. This is the first demonstration that Cyp1b1 as well as AhR is involved in the antiestrogenic effects of TCDD.[1]

References

  1. Role of the aryl hydrocarbon receptor and Cyp1b1 in the antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Takemoto, K., Nakajima, M., Fujiki, Y., Katoh, M., Gonzalez, F.J., Yokoi, T. Arch. Toxicol. (2004) [Pubmed]
 
WikiGenes - Universities