Circadian Rhythm of Acid Phosphatase Activity in Rat Liver Microsomes and Dependence of NADH 5α-Reductase on Phosphatase Activity

1984 ◽  
Vol 365 (2) ◽  
pp. 1271-1276 ◽  
Author(s):  
Volkmar GRAEF ◽  
Sighart W. GOLF
Keyword(s):  
Circadian Rhythm ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Acid Phosphatase Activity ◽  
Liver Microsomes ◽  
Rat Liver Microsomes

scholarly journals Fatty acyl-CoA esters inhibit glucose-6-phosphatase in rat liver microsomes

1995 ◽  
Vol 307 (2) ◽  
pp. 391-397 ◽  
Author(s):  
R Fulceri ◽  
A Gamberucci ◽  
H M Scott ◽  
R Giunti ◽  
A Burchell ◽  
...  
Keyword(s):  
Palmitic Acid ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Fatty Acyl ◽  
Rat Liver Microsomes ◽  
Control Value ◽  
Scattering Measurements ◽  
Induced Changes ◽  
Enzymic Assay

In native rat liver microsomes glucose 6-phosphatase activity is dependent not only on the activity of the glucose-6-phosphatase enzyme (which is lumenal) but also on the transport of glucose-6-phosphate, phosphate and glucose through the respective translocases T1, T2 and T3. By using enzymic assay techniques, palmitoyl-CoA or CoA was found to inhibit glucose-6-phosphatase activity in intact microsomes. The effect of CoA required ATP and fatty acids to form fatty acyl esters. Increasing concentrations (2-50 microM) of CoA (plus ATP and 20 microM added palmitic acid) or of palmitoyl-CoA progressively decreased glucose-6-phosphatase activity to 50% of the control value. The inhibition lowered the Vmax without significantly changing the Km. A non-hydrolysable analogue of palmitoyl-CoA also inhibited, demonstrating that binding of palmitoyl-CoA rather than hydrolysis produces the inhibition. Light-scattering measurements of osmotically induced changes in the size of rat liver microsomal vesicles pre-equilibrated in a low-osmolality buffer demonstrated that palmitoyl-CoA alone or CoA plus ATP and palmitic acid altered the microsomal permeability to glucose 6-phosphate, but not to glucose or phosphate, indicating that T1 is the site of palmitoyl-CoA binding and inhibition of glucose-6-phosphatase activity in native microsomes. The type of inhibition found suggests that liver microsomes may comprise vesicles heterogeneous with respect to glucose-6-phosphate translocase(s), i.e. sensitive or insensitive to fatty acid ester inhibition.

scholarly journals PURIFICATION OF GLUTARALDEHYDE ITS SIGNIFICANCE FOR PRESERVATION OF ACID PHOSPHATASE ACTIVITY

1968 ◽  
Vol 16 (3) ◽  
pp. 199-204 ◽  
Author(s):  
H. DARIUSH FAHIMI ◽  
PIERRE DROCHMANS ◽  
A. POPOWSKI
Keyword(s):  
Enzyme Activity ◽  
Acid Phosphatase ◽  
Enzymatic Activity ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Acid Phosphatase Activity ◽  
High Concentration ◽  
Liver Homogenates ◽  
Inorganic Phosphates

The inhibition of acid phosphatase activity in rat liver homogenates after fixation in different lots of commercial glutaraldehyde is determined and compared with the inhibition following fixation with a distilled product. It is shown that commercial glutaraldehydes inhibit more of the enzyme activity than the distilled product. The acidic products of oxidation of glutaraldehyde do not increase the inhibition of the enzymatic activity. The presence of high concentration of inorganic phosphates in different lots of commercial glutaraldehyde, as presented here, suggests that probably such impurities may be responsible for increased inhibition of phosphatase activity noted after fixation in commercial glutaraldehydes.

Changes in acid phosphatase activity in rat liver after ischemia

1989 ◽  
Vol 93 (2) ◽  
pp. 161-166 ◽  
Author(s):  
W. M. Frederiks ◽  
F. Marx
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Acid Phosphatase Activity

X-ray microanalysis of colloidal-gold-labelled lysosomes in rat liver sinusoidal cells after incubation for acid phosphatase activity

1980 ◽  
Vol 66 (2) ◽  
pp. 137-148 ◽  
Author(s):  
W. C. de Bruijn ◽  
J. P. M. Schellens ◽  
J. M. H. van Buitenen ◽  
J. van der Meulen
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Colloidal Gold ◽  
Acid Phosphatase Activity ◽  
Sinusoidal Cells ◽  
X Ray ◽  
Liver Sinusoidal Cells

scholarly journals Quantitative histochemical study of acid phosphatase activity in rat liver using a semipermeable membrane technique.

1987 ◽  
Vol 35 (2) ◽  
pp. 175-180 ◽  
Author(s):  
W M Frederiks ◽  
F Marx ◽  
G N Jonges ◽  
C J Van Noorden
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Acid Phosphatase Activity ◽  
Enzyme Inhibitors ◽  
Semipermeable Membrane ◽  
Coupling Technique ◽  
Lysosomal Acid ◽  
Membrane Technique ◽  
Post Coupling

Acid phosphatase activity has been demonstrated in rat liver with the semipermeable membrane technique using naphthol AS-BI phosphate as substrate and hexazotized pararosaniline (HPRA) as simultaneous coupling agent. With this method the final reaction product (FRP) appeared in rat liver as intensely colored red granules in liver parenchymal cells and in Küpffer cells. The absorbance spectrum of the FRP peaks between 510 and 550 nm. A nonspecific reaction product, as has been found in skeletal muscle, did not occur in rat liver. A substrate concentration of 5 mM and a HPRA concentration of 10 mM result in optimum localization and activity. We concluded from the results with different enzyme inhibitors that lysosomal acid phosphatase was demonstrated. The mean absorbance of the FRP increased linearly with incubation time (15-60 min). Furthermore, we found a linear increase of the FRP with increasing section thickness (4-10 micron). When the simultaneous coupling method was replaced by a post-coupling technique, the colored reaction product was diffusely located throughout the cytoplasm. In conclusion, the simultaneous coupling technique in combination with the semipermeable membrane method is a valuable tool for detecting and quantifying lysosomal acid phosphatase activity in rat liver. We demonstrated that acid phosphatase activity is 1.2 times higher periportally than pericentrally in rat liver, and that 24 hr fasting before the experiments did not change the acid phosphatase activity.

Aqueous extract of Securidaca longepedunculata root induce redox imbalance in male rat liver and kidney

2010 ◽  
Vol 29 (8) ◽  
pp. 679-688 ◽  
Author(s):  
TO Ajiboye ◽  
AK Salau ◽  
MT Yakubu ◽  
AT Oladiji ◽  
MA Akanji ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Aqueous Extract ◽  
Acid Phosphatase Activity ◽  
Male Rat ◽  
Antioxidant Systems ◽  
Liver And Kidney ◽  
Securidaca Longepedunculata ◽  
Serum Acid Phosphatase

The effect of aqueous extract of Securidaca longepedunculata root on redox homeostasis in male rat liver and kidney was investigated. Rats were grouped into four: A, B, C and D, where A (the control) received orally 1 mL of distilled water; B, C and D (test groups) received orally 200, 400 and 800 mg/kg body weight of the extract, respectively, for 28 days. Extract administration significantly reduced (p < .05) alkaline phosphatase activity in the liver and kidney with corresponding increases in the serum. Acid phosphatase activity increased significantly (p < .05) in the liver and kidney, while there was no significant change (p > .05) in the serum acid phosphatase activity. There was also significant decrease (p < .05) in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase in the liver and kidney. Liver and kidney levels of GSH, vitamins C and E were also significantly reduced (p < .05). Serum malonidialdehyde and lipid hydroperoxide increased significantly (p < .05) in all the extract-treated groups. The available data from this study revealed that aqueous extract of S. longepedunculata root exerted its toxicity in the animals by depleting the antioxidant systems. This may consequently expose the cells and cellular macromolecules to oxidative damage by reactive oxygen species generated either from the metabolism of the extract or other in vivo means.

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