scholarly journals Further observations on the activation of lysosomal acid α-glucosidase by cortisone derivatives

1973 ◽  
Vol 132 (3) ◽  
pp. 435-438 ◽  
Author(s):  
E. J. Bourne ◽  
K. Clarke ◽  
J. B. Pridham ◽  
J. J. M. Rowe
Keyword(s):  
Acid Phosphatase ◽  
Rat Liver ◽  
Lysosomal Membrane ◽  
Cortisone Acetate ◽  
Lysosomal Acid ◽  
Liver Slices ◽  
Liver Lysosomes ◽  
Membrane Bound ◽  
Isolated Liver

1. Cortisone acetate activates the acid α-glucosidase in rat liver slices and in isolated liver lysosomes. 2. The reaction is steroid specific and moreover does not occur with lysosomal acid phosphatase or β-galactosidase. 3. After pretreatment of the lysosomes with cortisone, substrate (maltose) binding to the soluble lysosomal acid α-glucosidase is not affected, but the steroid does increase the Vmax. value. Membrane-bound enzyme is not activated by cortisone. 4. 4-[14C]Cortisone is preferentially bound to the lysosomal membrane and the possible involvement of this structure in the activation phenomenon is discussed.

Effect of Glycyrrhizin on Lysosomes Labilization by Phospholipase A2

1986 ◽  
Vol 14 (03n04) ◽  
pp. 131-137 ◽  
Author(s):  
Yasuko Shiki ◽  
Yo Ishikawa ◽  
Kohji Shirai ◽  
Yasushi Saito ◽  
Sho Yoshida
Keyword(s):  
Acid Phosphatase ◽  
Phospholipase A2 ◽  
Rat Liver ◽  
Lysosomal Membrane ◽  
Phospholipase A ◽  
Ph Optimum ◽  
Liver Lysosomes ◽  
Inhibited Acid ◽  
Rat Liver Lysosomes

The influence of glycyrrhizin on the effect of phospholipase A2 on lysosomes was studied. Treatment of rat liver lysosomes with venom phospholipase A2 caused release of acid phosphatase. This release of acid phosphatase was inhibited by 0.1 mM glycyrrhizin. Glycyrrhizin also inhibited acid phospholiase A2 with pH optimum of 4.5, which is thought to be present in the lysosomal membrane. These results suggests that glycyrrhizin stabilizes lysosomes by inhibiting phospholipase A2 activity in the lysosomal membrane.

scholarly journals Effect of a transitory ischaemia on the structure-linked latency of rat liver acid phosphatase and β-galactosidase

1981 ◽  
Vol 196 (3) ◽  
pp. 861-866 ◽  
Author(s):  
R Wattiaux ◽  
S Wattianx-De Coninck
Keyword(s):  
Blood Flow ◽  
Acid Phosphatase ◽  
Distribution Pattern ◽  
Rat Liver ◽  
Differential Centrifugation ◽  
Liver Lysosomes ◽  
Secondary Rise ◽  
Beta Galactosidase ◽  
Free Activity ◽  
Normal Latency

The structure-linked latency of acid phosphatase and beta-galactosidase was studied in rat liver lobes made ischaemic for 1 or 2 h and then recirculated with blood for increasing periods. Free activity of acid phosphatase and unsedimentable activity of beta-galactosidase are increased in homogenates of ischaemic livers. When ischaemia had been maintained for 1 h, the recovery of normal latency for both enzymes was observed 1 h after re-establishment of the blood flow. After a 2 h period of ischaemia, unmasked activity markedly decreases during the first 1 h after restoration of blood flow; after that, a large and irreversible secondary rise takes place. Chlorpromazine, injected 30 min before or just after induction of ischaemia, extensively prevents the latency decrease occurring during restoration of blood flow. Modifications of the hydrolase distribution pattern obtained after differential centrifugation are in agreement with the latency changes. These results suggest that a 2 h ischaemia causes an alteration of the liver lysosomes that is largely reversible and that restoration of blood flow induces an irreversible alteration of these organelles. Chlorpromazine treatment prevents the irreversible lesion from taking place.

Effect of Bilateral Nephrectomy on Urea Formation in Rat Liver Slices

1957 ◽  
Vol 191 (2) ◽  
pp. 345-349 ◽  
Author(s):  
Alvin L. Sellers ◽  
Joseph Katz ◽  
Jessie Marmorston
Keyword(s):  
Rat Liver ◽  
Liver Protein ◽  
Urea Synthesis ◽  
Bilateral Nephrectomy ◽  
Liver Slices ◽  
Isolated Liver ◽  
Intact Rats

The rate of urea synthesis by isolated liver slices has been determined. The rate of urea synthesis is approximately 50% greater in liver slices from nephrectomized rats than in those from nonuremic controls. Liver slices from intact rats maintained on a diet of 15% glucose formed only 23–50% as much urea as slices from fasted controls. The results indicate that the increased urea synthesis in liver slices from nephrectomized rats is largely due to an increase in the catabolism of liver protein resulting in an increase in urea precursors.

scholarly journals The permeability of lysosomes to sugars. Effect of diethylstilbestrol on the osmotic activation of lysosomes induced by glucose

1989 ◽  
Vol 262 (3) ◽  
pp. 981-984 ◽  
Author(s):  
M Jadot ◽  
S Wattiaux-De Coninck ◽  
R Wattiaux
Keyword(s):  
Plasma Membrane ◽  
Glucose Transport ◽  
Rat Liver ◽  
Lysosomal Membrane ◽  
Liver Lysosomes ◽  
Unspecific Binding ◽  
Rat Liver Lysosomes

We have investigated the effect on the osmotic activation of rat liver lysosomes, by glucose penetration, of different substances known to inhibit the glucose transport through the plasma membrane. Diethylstilbestrol is the most efficient, particularly when purified lysosomes are used. It has no effect on osmotic activation induced by hypo-osmotic sucrose or by iso-osmotic KCl. It is proposed that diethylstilbestrol reacts with specific sites involved in the glucose translocation through the lysosomal membrane. These sites could not be identified by binding experiments, presumably owing to the considerable unspecific binding of the compound to the membrane.

Soluble and Membrane-Bound Enzyme-Active Antigens of Rat-Liver Lysosomes

1975 ◽  
Vol 51 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Klavs BERZINS ◽  
Fred BLOMBERG ◽  
Peter PERLMANN
Keyword(s):  
Rat Liver ◽  
Liver Lysosomes ◽  
Membrane Bound ◽  
Rat Liver Lysosomes

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.

Isolation and sequencing of a cDNA clone encoding acid phosphatase in rat liver lysosomes

1989 ◽  
Vol 162 (3) ◽  
pp. 1044-1053 ◽  
Author(s):  
Masaru Himeno ◽  
Hideaki Fujita ◽  
Youichiro Noguchi ◽  
Akira Kono ◽  
Keitaro Kato
Keyword(s):  
Acid Phosphatase ◽  
Rat Liver ◽  
Cdna Clone ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes

Effect of ovarian hormones on lysosomal acid hydrolase activities in rat myometrium.

1977 ◽  
Vol 232 (4) ◽  
pp. E423
Author(s):  
B F Sloane ◽  
J W Bird
Keyword(s):  
Acid Phosphatase ◽  
Cathepsin D ◽  
Hormone Replacement ◽  
Membrane Integrity ◽  
Lysosomal Membrane ◽  
Acid Hydrolase ◽  
Acid Hydrolases ◽  
Lysosomal Acid ◽  
Hypophysectomized Rats ◽  
Estrus Stage

The activities of the lysosomal acid hydrolases-cathespin D, acid phosphatase, beta-N-acetylglucosaminidase, and beta-glucuronidase-were measured in rat myometrium under the following hormonal conditions: during the estrus stage of the estrous cycle (NE); at 1,2, and 3 wk after ovariectomy; and in 3-wk postovariectomized females after hormone replacement therapy with 17 beta-estradiol (E2), progesterone (P), or E2 + P. Activities per milligram protein and per milligram DNA of the enzymes were significantly decreased after ovariectomy and were restored to the NE level or above after injecting E2 or E2 + P. Lysosomal enzyme activities did not change with hormonal state in hypophysectomized rats, suggesting that other hormones are required for mediation of enzyme activity. Acid hydrolase activities in other tissues and nonlysosomal enzyme activites in the myometrium did not fluctuate with hormonal state. Studies of lysosomal membrane integrity suggested that one population of lysosomes richer in cathepsin D and acid phosphatase and another rich in beta-N-acetylglucosaminidase and beta-glucuronidase may be present in rat myometrium. Estrogen seemed to labilize the lysosomal membrane of at least the latter of the two proposed populations of myometrial lysosomes.

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