Study of histochemical and biochemical changes in the liver of rats induced by high doses of isoprenaline.
The aim of the present work was to study by means of histochemical and chemical methods the 7-day course of changes in carbohydrate metabolism in the liver of male rats induced by a single dose of isoprenaline of 50 mg/kg administered subcutaneously. A statistically significant reduction was seen both in the level of free glycogen and lactate within 24 hours. The decrease of pyruvate level was not so marked. At the same time, there was increased, and within the hepatic lobules also extended activity of enzymes catalyzing glycogenolysis, i.e. alpha-glucan phosphorylase and particularly the branching Q-enzyme, glucose-6-phosphatase and LDH, whereas the level of malate and activity of SDH, which are constituents of the Krebs cycle, were found to be reduced. Cytochrome oxidase activity was changed after 24 hr compared to the controls. The obtained results indicate that an extensive glycogenolysis occurs in the liver of rats in the 24 hr following s.c. administration of isoprenaline, the major part of liver glycogen being degraded through glucose-6-phosphate to blood glucose and its metabolism via the Krebs cycle reduced. The observed metabolic changes are of reversible character and tend to normalize over the 2nd and 3rd day following isoprenaline administration.
D015061:1,4-alpha-Glucan Branching Enzyme / Q000378:metabolism; D000818:Animals; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D006005:Phosphorylases / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism*; D051381:Rats
D007773:Lactates; D011773:Pyruvates; D006003:Glycogen; D007770:L-Lactate Dehydrogenase; D006005:Phosphorylases; D015061:1,4-alpha-Glucan Branching Enzyme; D005952:Glucose-6-Phosphatase; D007545:Isoproterenol