Influence of Age and Spironolactone on Lysosomal Enzyme Activities, DNA and Protein Content of the Rat Liver after Partial Hepatectomy

Gerontology ◽  
1979 ◽  
Vol 25 (2) ◽  
pp. 87-93 ◽  
Author(s):  
D. Platt ◽  
F. Gross-Fengels
Keyword(s):  
Protein Content ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Lysosomal Enzyme ◽  
Enzyme Activities

scholarly journals Folate metabolism in the rat liver during regeneration after partial hepatectomy

1975 ◽  
Vol 152 (2) ◽  
pp. 229-232 ◽  
Author(s):  
Bruno Barbiroli ◽  
Carla Bovina ◽  
Brunella Tolomelli ◽  
Mario Marchetti
Keyword(s):  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Enzyme Activities ◽  
Dark Period ◽  
Folate Metabolism ◽  
Regeneration Process ◽  
Period 2 ◽  
Serine Hydroxymethyl Transferase ◽  
Early Phases

1. Folate metabolism was studied during the early phases of liver regeneration after partial hepatectomy in rats accustomed to eating during the first 8h of a daily 12h dark period. 2. The content of 5-CH3–H4folate was drastically decreased during the first hours of regeneration. 3. The total HCO–H4folate coenzymes showed a constant decrease during the first 3 days of regeneration, and a continuous interconversion between 5-HCO–H4folate and 10-HCO–H4folate. 4. 10-HCO–H4folate synthetase, serine hydroxymethyl-transferase and 5,10-CH2–H4folate dehydrogenase activities were relatively low during the first hours after the operation, and increased only several hours later. 5. The increase in enzyme activities showed a stepwise pattern, apparently due to an interaction between the regeneration process and the controlled feeding schedules.

scholarly journals Purification and immunological quantification of rat liver lysosomal glycosidases

1989 ◽  
Vol 264 (1) ◽  
pp. 115-123 ◽  
Author(s):  
P C de Groen ◽  
G D LeSage ◽  
P S Tietz ◽  
N F LaRusso
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Molecular Sieve ◽  
Polyacrylamide Gel Electrophoresis ◽  
Enzyme Concentration ◽  
Regulatory Control ◽  
Beta Galactosidase ◽  
Lysosomal Glycosidases

Although lysosomal enzyme activities are known to vary in response to numerous physiological and pharmacological stimuli, the relationship between lysosomal enzyme activity and enzyme concentration has not been systematically studied. Therefore we developed radioimmunoassays for two lysosomal glycosidases in order to determine lysosomal enzyme concentration. beta-Galactosidase and beta-glucuronidase were purified from rat liver 2780-fold and 1280-fold respectively, by using differential centrifugation, affinity chromatography, ion-exchange chromatography and molecular-sieve chromatography. Polyclonal antibodies to these enzymes were raised in rabbits, and two radioimmunoassays were established. Antibody specificity was shown by: (i) selective immunoprecipitation of enzyme activity; (ii) identical bands of purified enzyme on SDS/polyacrylamide-gel electrophoresis and immunoelectrophoresis; (iii) single immunoreactive peaks in molecular-sieve chromatography experiments. Sensitivities of the assays were such that 15 ng of beta-galactosidase and 45 ng of beta-glucuronidase decreased the ratio of bound to free radiolabel by 50%; minimal detectable amounts of immunoreactive enzymes were 2 ng and 10 ng respectively. The assays were initially used to assess the effects of physiological perturbations (i.e. fasting and age) on enzyme concentrations in rat liver; these experiments showed that changes in enzyme concentrations do not always correlate with changes in enzyme activities. This represents the first report of radioimmunoassays for lysosomal glycosidases. The results suggest that these radioimmunoassays provide useful technology for the study of regulatory control mechanisms of the concentrations of lysosomal glycosidases in mammalian tissues.

REGULATION OF THE ACTIVITIES OF THE ENZYMES INVOLVED IN THE METABOLISM OF STEROID HORMONES IN RAT LIVER: THE EFFECT OF 19-NORTESTOSTERONE AND THE INFLUENCE OF CYPROTERONE ACETATE ON THE ACTION OF TESTOSTERONE AND 5α-DIHYDROTESTOSTERONE

1974 ◽  
Vol 77 (2) ◽  
pp. 287-297 ◽  
Author(s):  
Rüdiger Ghraf ◽  
Edmund Rodney Lax ◽  
Hanns-Georg Hoff ◽  
Herbert Schriefers
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Rat Liver ◽  
Enzyme Activities ◽  
Cyproterone Acetate ◽  
Hydroxysteroid Dehydrogenase ◽  
Seminal Vesicles ◽  
Normal Male ◽  
Steroid Hydroxylases ◽  
Drug Leads

ABSTRACT The androgens testosterone and 5α-dihydrotestosterone, the anabolic drug 19-nortestosterone and the anti-androgen cyproterone acetate were investigated with regard to their modifying action on the sexual differentiation of the activities of rat liver enzymes involved in steroid hormone metabolism. The activities of the enzymes (Δ4-5α-hydrogenase, 20-ketoreductase, 3α-and 3β-hydroxysteroid dehydrogenase, NAD- and NADP-dependent Δ4-3β-hydroxysteroid dehydrogenase, total steroid hydroxylases, 7α- and 16α-hydroxylase) were determined in cell-free liver fractions of male animals castrated on day 25 of life and killed on day 90; and of castrated animals which, from day 75 to 89 received daily sc injections (0.3 mg/100 g body weight) of the anabolic drug or the androgen only or in combination with cyproterone acetate (3 mg/100 g body weight). With the exception of 7α-hydroxylase castration leads to a feminization of the enzyme activity pattern. However, the degree of feminization varies from enzyme to enzyme. The administration of testosterone or of 5α-dihydrotestosterone reverses the effect of castration. With 5α-dihydrotestosterone activity values were reached which in some cases were significantly higher than those obtained with testosterone. Although both androgens restored the enzyme activities to the normal male values, neither androgen was able to compensate for the weight loss of the seminal vesicles in the dose administered. The administration of 19-nortestosterone in the same dose as testosterone is only 30 % as effective in restoring the weight loss of the seminal vesicles, but leads to identical activities of Δ4-5α-hydrogenase and of hydroxysteroid dehydrogenases as are found for testosterone. 19-Nortestosterone is without influence on the activities of total steroid hydroxylases and of 16α-hydroxylase. 16α-Hydroxylase is the only enzyme in which the activity enhancing effects of testosterone or of 5α-dihydrotestosterone can be completely blocked by the simultaneous administration of the anti-androgen cyproterone acetate. In all other enzyme activities the anti-androgen does not interfere with the effect of the androgens although it blocks their action on the weight restitution of the seminal vesicles by 60–70 %. 7α-Hydroxylase does not exhibit any androgen dependency. Neither castration nor the subsequent administration of the two androgens, or of the anabolic drug leads to any alterations in activity. However, it is interesting to note that the administration of cyproterone acetate does cause an increase in activity.

Gender dimorphism in rat liver mitochondrial oxidative metabolism and biogenesis

2005 ◽  
Vol 289 (2) ◽  
pp. C372-C378 ◽  
Author(s):  
Roberto Justo ◽  
Jordi Boada ◽  
Margalida Frontera ◽  
Jordi Oliver ◽  
Jordi Bermúdez ◽  
...  
Keyword(s):  
Gender Differences ◽  
Protein Content ◽  
Rat Liver ◽  
Oxidative Metabolism ◽  
Mitochondrial Protein ◽  
Electron Microscopic ◽  
Gender Dimorphism ◽  
Protein Levels ◽  
Mitochondrial Fractions ◽  
Mitochondrial Oxidative Metabolism

In the present study, we have investigated gender differences in rat liver mitochondrial oxidative metabolism. Total mitochondrial population (M) as well as the heavy (M1), medium (M3), and light (M8) mitochondrial fractions obtained by means of differential centrifugation steps at 1,000, 3,000, and 8,000 g, respectively, were isolated. Electron microscopic analysis was performed and mitochondrial protein content and cardiolipin levels, mitochondrial O2 flux, ATP synthase activity, mitochondrial membrane potential, and mitochondrial transcription factor A (TFAM) protein levels were measured in each sample. Our results indicate that mitochondria from females have higher protein content and higher cardiolipin levels, greater respiratory and phosphorylative capacities, and more-energized mitochondria in respiratory state 3. Moreover, protein levels of TFAM were four times greater in females than in males. Gender differences in the aforementioned parameters were more patent in the isolated heavy M1 and M3 mitochondrial fractions. The present study demonstrates that gender-related differences in liver mitochondrial function are due mainly to a higher capacity and efficiency of substrate oxidation, likely related to greater mitochondrial machinery in females than in males, which is in accord with greater mitochondrial differentiation in females.

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