Studies on glucose-6-phosphatase, fructose-1,6-diphosphatase activity, glycogen distribution and endoplasmic reticulum changes during hexachlorocyclohexane induced hepatocarcinogenesis in pure inbred Swiss mice.
Inbred Swiss mice were fed hexachlorocyclohexane (BHC) at 500 ppm dose level in diet for 2, 4, 6 and 8 months. Later BHC was discontinued for 4 months and subsequently the animals were refed BHC for 1 month. Glucose-6-phosphatase (G6Pase) and fructose-1,6-diphosphatase (FDPase) activity was studied at different time intervals accompanied with changes in glycogen distribution and endoplasmic reticulum (ER) proliferation in hepatocytes. G6Pase and FDPase showed a decline in activities on BHC feeding. The activities of these enzymes showed recovery on BHC discontinuation. The changes were progressive with duration of exposure. After 6 months exposure the biochemical changes became more resistant to recovery. Maximal changes occurred in 8 month-exposure and the changes were irreversible. Glycogen accumulation and depletion followed a definite pattern. After two months of BHC feeding, increase in parenchymal glycogen storage zones was observed. In the later stage of hepatocarcinogenesis and specially in tumors, glycogen was depleted considerably. Smooth endoplasmic reticulum (SER) proliferation was recorded around the 3rd and 4th month. The correlation between glycogen accumulation, SER proliferation, G6Pase and FDPase activity is discussed.
D000818:Animals; D002273:Carcinogens; D004334:Drug Administration Schedule; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D005952:Glucose-6-Phosphatase / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D001556:Hexachlorocyclohexane / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008113:Liver Neoplasms / Q000139:chemically induced*; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000139:chemically induced; D013997:Time Factors
D002273:Carcinogens; D001556:Hexachlorocyclohexane; D006003:Glycogen; D006597:Fructose-Bisphosphatase; D005952:Glucose-6-Phosphatase