Genetic and biochemical studies on hepatocytes of young and old heat-stressed rats

Heat stress was shown to cause impairments in hepatocytes and result in oxidative damage, which can lead to cytotoxicity; thus, we carried out this study to investigate the age tolerance to oxidative stress caused by heat stress in young and old female Wistar rats and whether this effect varied with different postexposure periods. Heat stress-induced injury in hepatic cells was evaluated in young [6 months] and old [24 months] female Wistar rats by exposing them at an ambient temperature of 42[degree sign]C for 1 h. Livers were harvested at several time points [6, 24, and 72 h] after application of the heat stress protocol. The level of DNA damage assessed using the comet assay, percentage of fragmented DNA, quantitative changes in nucleic acid and protein contents, activity of liver enzyme marker, level of superoxide dismutase, and lipid peroxidation were determined. The results showed that exposure to heat stress significantly increased the oxidative DNA damage, percentage of DNA fragmentation, and activities of liver enzyme marker and stimulated the process of lipid peroxidation in liver cells of young and old rats. Further, it decreased total nucleic acid and protein contents and superoxide dismutase activities. In addition, it was observed that the damage from heat stress was more serious in old animals than in young ones and they needed more time to return to control values. It was concluded that aging and heat exposure instigate oxidative stress, which can contribute to cellular dysfunction and age-related reductions in stress tolerance

Cytogenetic and biochemical studies on the effect of DDB in albino mice and their embryos

DDB [Dimethyl - 4,4 - dimethoxy - 5,6,5,6 - dimethlene - dioxybiphenyl - 2,2 - dicarboxylate] is important drug of medicine not expensive since large number of people are using it in virus B and C cases for very large periods extend to many years. The protective of DDB on chemically induced damage was studied in primary cultures of mammals hepatocytes. This work study of cytogenetic and biochemical effect of DDB, in mice using the chromosomes of bone marrow of male and pregnant female shown some changes with liver embryos. Also germ cells of testes given non significant aberration when compared with control. As well as some biochemical parameters in serum and tissues, shown non significant changes in nucleic acid, total protein, total cholesterol, total glucose, total triglycerides and lactate dehydrogenase [LDH]. Also, enzyme analysis of liver function and kidney