Low dose effects of dichlorodiphenyltrichloroethane (DDT) on gene transcription and DNA methylation in the hypothalamus of young male rats: implication of hormesis-like effects.

To verify the relationship between oxidative stress and DNA methylation in the young brain, dichlorodiphenyltrichloroethane (DDT) was administered by gavage to male young rats at doses of 0, 0.006, 0.06, 0.

The effect of testosterone propionate supplement on testicular toxicity with thiamphenicol in male Sprague-Dawley rats.

Testosterone propionate (TP) was supplemented to male rats for assessment of its ameliorating effect on testicular toxicity with thiamphenicol (TAP). A total of 20 male Sprague-Dawley rats were treated orally with TAP at 200 mg/kg/day for up to 4 weeks. In addition, 5 male rats were allotted to the control group receiving vehicle only.

Mechanisms of promotion and progression of preneoplastic lesions in hepatocarcinogenesis by DDT in F344 rats.

Time-related changes in potential factors involved in hepatocarcinogenesis by DDT were investigated in a 4-week and a 2-year feeding studies of p,p'-DDT with F344 rats. In the 4-week study with males at doses of 50, 160, and 500 ppm, cell proliferation and gap junctional intercellular communication (GJIC) were examined after 1, 2, 3, 7, 14, and 28 days. Cell proliferation was enhanced within 3 days at any dose level, but returned to normal after 7 days, whereas GJIC was inhibited throughout the study.

Thymic atrophy induced by methoxychlor in rat pups.

The effect of Methoxychlor (MXC) on the thymus was examined in rat pups that were delivered from dams receiving MXC at a dietary concentration of 0 or 1500 ppm for a period from pregnancy to lactation. The pups of both sexes were euthanized on postnatal days (PNDs) 7, 14, and 21. Histologically, the thymus showed marked depletion of cortical lymphocytes on PND 7 and also had an increase in lymphophagocytosis in the cortical area on PNDs 14 and 21.

Pulmonary sequestration with ectopic pancreatic tissue in a Wistar Hannover GALAS rat.

A multicystic mass of the lung was found in a male 11-week-old Wistar Hannover GALAS rat. The cystic mass was located in the region of the right caudal lobe and had no direct communication with the tracheobranchial tree. Histologically, the pulmonary mass was composed of variably sized cysts containing mucinous material, cellular debris, erythrocytes, and inflammatory cells.