A cytochemical study of the livers of rats treated with diethylnitrosamine/phenobarbital, with benzidine/phenobarbital, with phenobarbital, or with clofibrate

Effects of the Peroxisome Proliferator Di(2-Ethylhexyl)Phthalate on Enzymes in Rat Liver and on Carcinogen-Induced Liver Altered Foci in Comparison to the Promoter Phenobarbital

“…These differences in effects of DEHP and PB support the findings of Mompon et al (14) in a somewhat similar study, that clofibrate increased 2-glycerophosphate dihydrogenase, whereas PB did not. Thus, the biochemical effects in the liver of peroxisome-proliferators differ from those of a typical liver neoplasm promoter.…”

“…This reduction is similar to our previous findings with another peroxisome proliferator, nafenopin (1 6). In other studies, nodules (adenomas) and hepatocellular carcinomas induced by the peroxisome proliferator Wy- 14,643 have been found to be negative for GGT (22). In contrast to the reduction of GGT by peroxisome proliferators, activity in penportal hepatocytes can be increased by other xenobiotics such as butylated hydroxytoluene (7) and butylated hydroxanisole (40), as well as by PB (16,24), as in the present study.…”

Effects of the Peroxisome Proliferator Di(2-Ethylhexyl)Phthalate on Enzymes in Rat Liver and on Carcinogen-Induced Liver Altered Foci in Comparison to the Promoter Phenobarbital

“…These differences in effects of DEHP and PB support the findings of Mompon et al (14) in a somewhat similar study, that clofibrate increased 2-glycerophosphate dihydrogenase, whereas PB did not. Thus, the biochemical effects in the liver of peroxisome-proliferators differ from those of a typical liver neoplasm promoter.…”

“…This reduction is similar to our previous findings with another peroxisome proliferator, nafenopin (1 6). In other studies, nodules (adenomas) and hepatocellular carcinomas induced by the peroxisome proliferator Wy- 14,643 have been found to be negative for GGT (22). In contrast to the reduction of GGT by peroxisome proliferators, activity in penportal hepatocytes can be increased by other xenobiotics such as butylated hydroxytoluene (7) and butylated hydroxanisole (40), as well as by PB (16,24), as in the present study.…”

Post-translational Regulation of Glucose-6-phosphate Dehydrogenase Activity in (Pre)neoplastic Lesions in Rat Liver

“…Rapid upregulation of G6PD activity at the post-translational level was demonstrated after treatment of animals or cells with hormones (Lombardi et al 2000), GSH-depleting agents (Salvemini et al 1999), and growth factors (Stanton et al 1991). In our model, DENA was administered to rats to induce (pre)neoplasms in livers, and it has been established that an early effect of DENA is depletion of reduced glutathione (Mompon et al 1987). A direct consequence of increased G6PD activity is regeneration of reduced glutathione.…”

A Metabonomics Study of the Hepatotoxicants Galactosamine, Methylene Dianiline and Clofibrate in Rats*

“…Of these, methylene dianiline and galactosamine are model compounds for the induction of bile duct damage and hepatocyte death, respectively, in a reproducible and dose‐dependent manner in experimental animals (Keppler et al 1974; Kanz et al 1992 & 1995; Beckwith‐hall et al 1998). Clofibrate is a well‐documented hepatotoxicant that causes peroxisome proliferation and tumours without necrosis in the rodent liver (Mompon et al 1987).…”

Effects of the Peroxisome Proliferator Di(2-Ethylhexyl)Phthalate on Enzymes in Rat Liver and on Carcinogen-Induced Liver Altered Foci in Comparison to the Promoter Phenobarbital

“…These differences in effects of DEHP and PB support the findings of Mompon et al (14) in a somewhat similar study, that clofibrate increased 2-glycerophosphate dihydrogenase, whereas PB did not. Thus, the biochemical effects in the liver of peroxisome-proliferators differ from those of a typical liver neoplasm promoter.…”

“…This reduction is similar to our previous findings with another peroxisome proliferator, nafenopin (1 6). In other studies, nodules (adenomas) and hepatocellular carcinomas induced by the peroxisome proliferator Wy- 14,643 have been found to be negative for GGT (22). In contrast to the reduction of GGT by peroxisome proliferators, activity in penportal hepatocytes can be increased by other xenobiotics such as butylated hydroxytoluene (7) and butylated hydroxanisole (40), as well as by PB (16,24), as in the present study.…”

Post-translational Regulation of Glucose-6-phosphate Dehydrogenase Activity in (Pre)neoplastic Lesions in Rat Liver

“…Rapid upregulation of G6PD activity at the post-translational level was demonstrated after treatment of animals or cells with hormones (Lombardi et al 2000), GSH-depleting agents (Salvemini et al 1999), and growth factors (Stanton et al 1991). In our model, DENA was administered to rats to induce (pre)neoplasms in livers, and it has been established that an early effect of DENA is depletion of reduced glutathione (Mompon et al 1987). A direct consequence of increased G6PD activity is regeneration of reduced glutathione.…”

A Metabonomics Study of the Hepatotoxicants Galactosamine, Methylene Dianiline and Clofibrate in Rats*

“…Of these, methylene dianiline and galactosamine are model compounds for the induction of bile duct damage and hepatocyte death, respectively, in a reproducible and dose‐dependent manner in experimental animals (Keppler et al 1974; Kanz et al 1992 & 1995; Beckwith‐hall et al 1998). Clofibrate is a well‐documented hepatotoxicant that causes peroxisome proliferation and tumours without necrosis in the rodent liver (Mompon et al 1987).…”

Effects of the Peroxisome Proliferator Di(2-Ethylhexyl)Phthalate on Enzymes in Rat Liver and on Carcinogen-Induced Liver Altered Foci in Comparison to the Promoter Phenobarbital

“…These differences in effects of DEHP and PB support the findings of Mompon et al (14) in a somewhat similar study, that clofibrate increased 2-glycerophosphate dihydrogenase, whereas PB did not. Thus, the biochemical effects in the liver of peroxisome-proliferators differ from those of a typical liver neoplasm promoter.…”

“…This reduction is similar to our previous findings with another peroxisome proliferator, nafenopin (1 6). In other studies, nodules (adenomas) and hepatocellular carcinomas induced by the peroxisome proliferator Wy- 14,643 have been found to be negative for GGT (22). In contrast to the reduction of GGT by peroxisome proliferators, activity in penportal hepatocytes can be increased by other xenobiotics such as butylated hydroxytoluene (7) and butylated hydroxanisole (40), as well as by PB (16,24), as in the present study.…”

Post-translational Regulation of Glucose-6-phosphate Dehydrogenase Activity in (Pre)neoplastic Lesions in Rat Liver

“…Rapid upregulation of G6PD activity at the post-translational level was demonstrated after treatment of animals or cells with hormones (Lombardi et al 2000), GSH-depleting agents (Salvemini et al 1999), and growth factors (Stanton et al 1991). In our model, DENA was administered to rats to induce (pre)neoplasms in livers, and it has been established that an early effect of DENA is depletion of reduced glutathione (Mompon et al 1987). A direct consequence of increased G6PD activity is regeneration of reduced glutathione.…”

A Metabonomics Study of the Hepatotoxicants Galactosamine, Methylene Dianiline and Clofibrate in Rats*

“…Of these, methylene dianiline and galactosamine are model compounds for the induction of bile duct damage and hepatocyte death, respectively, in a reproducible and dose‐dependent manner in experimental animals (Keppler et al 1974; Kanz et al 1992 & 1995; Beckwith‐hall et al 1998). Clofibrate is a well‐documented hepatotoxicant that causes peroxisome proliferation and tumours without necrosis in the rodent liver (Mompon et al 1987).…”