OBJECTIVES The aim of the study has been to explore hemimellitene distribution in blood, liver, lung and kidney as well as toxicokinetics of its elimination from blood of rats after single and repeated inhalation exposure to this compound. Tissue distribution and excretion with urine of 2-dimethylbenzoic acids (2,3-DMBA and 2,6-DMBA) were also evaluated. MATERIAL AND METHODS Male outbred IMP:...

UNLABELLED Pharmacologic and global gene deletion studies demonstrate that cyclooxygenase-2 (PTGS2/COX-2) plays a critical role in DMBA/TPA-induced skin tumor induction. Although many cell types in the tumor microenvironment express COX-2, the cell types in which COX-2 expression is required for tumor promotion are not clearly established. Here, cell type-specific Cox-2 gene deletion reveals a ...

The SENCAR mouse stock was selectively bred for eight generations for sensitivity to skin tumor induction by the two-stage tumorigenesis protocol using 7,12-dimethylbenz(a)anthracene (DMBA) as the initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as the promoter. The SENCAR mouse was derived by crossing Charles River CD-1 mice with skin-tumor-sensitive mice (STS). The SENCAR mice are muc...

The present study was designed to elucidate differences in the mechanism of the induction of mouse skin tumors either by the initiation-promotion regimen or by the complete carcinogenesis process. The protocols used to elicit skin tumors were: (a) by the initiation-promotion regimen, a single application of 0.2 ,umol of 7,12-dimethylbenz[a]anthracene (DMBA) followed by twice-weekly applications...

The sensitivity of A/HeJ, AKR/J, C3H/HeJ, C57BL/6J, C58/J, and DBA/2J male mice to single i.p. injections of 7,12dimethylbenz[a]anthracene (DMBA) was investigated. The drug was administered in a single dose of 0.75 to 3 mg per mouse and animals were sacrificed 5-20 days after injection. The AKR mice were least affected by DMBA. Acute ]>eritoneal inflamma tion accompanied by accumulation of an e...

Glutathione S-transferases (GSTs) are the products of a multigene family. A well-established function of GSTs is to metabolize carcinogens by catalysing the conjugation of electrophilic substrates to glutathione. Whether placental GST (GST-P) is expressed during the promotion of two-stage hamster buccal-pouch mucosa (HBPM) carcinogenesis was investigated here, using 7,12-dimethylbenz[a]anthrace...

INTRODUCTION Oral carcinoma accounts for 40-50 percent of all cancers in India. Tobacco chewing, smoking and alcohol consumption are the major risk factors associated with the high incidence of oral cancer in India. Our aim was to investigate the chemopreventive potential of curcumin and piperine during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. METHODS...

Sprague-Dawley female rats were sacrificed at various times after the intragastric administration of 7 , 12-dimethylbenz(a)anthracene (DMBA>3H. The abdominal-inguinal mammary glands were removed, and the parenchymal cells were separated. Parenchymal cell DNA and protein were isolated, and the DNA was purified by density equilibrium centrifugation in cesium chloride. Sixteen hr after carcinogen ...

Fifty outbred Syrian golden hamsters were equally divided into three experimental groups and two control groups. The pouches of the experimental groups were painted bilaterally with a 0.5% 7,12-dimethylbenz[a]anthracene (DMBA) solution thrice a week for 3, 7 and 14 weeks. One of the control groups was applied with mineral oil while another control group remained untreated throughout the experim...