Alterations in cardiac lysosomal hydrolases following induction of the calcium paradox

1987 ◽  
Vol 65 (11) ◽  
pp. 2175-2181 ◽  
Author(s):  
Michael J. B. Kutryk ◽  
Naranjan S. Dhalla
Keyword(s):  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Lysosomal Enzymes ◽  
Cell Damage ◽  
Calcium Paradox ◽  
Free Medium ◽  
Lysosomal Hydrolases ◽  
Cardiac Damage ◽  
Rat Hearts ◽  
Reperfusion Period

Although perfusion of the heart with calcium-free medium for a brief period followed by reperfusion with calcium-containing medium results in marked structural derangements (calcium paradox), the mechanisms for this cell damage are far from clear. Since activation of lysosomal enzymes has been associated with pathological damage, it was the purpose of this study to examine alterations in the activities of several lysosomal enzymes in rat hearts subjected to calcium paradox. No significant changes in the activities of (β-acetylglucosaminidase, β-galactosidase, α-mannosidase, or acid phosphatase were seen in the homogenates of hearts exposed to the calcium paradox. However, there were dramatic alterations in the lysosomal enzyme activities in the sedimentable and nonsedimentable fractions during calcium paradox. The lysosomal enzyme activities were also detected in the perfusate collected during reperfusion with calcium-containing medium. These changes occurred during the reperfusion period since no alterations were apparent after calcium-free perfusion and were dependent upon the time of reperfusion with medium containing Ca2+ as well as the time of perfusion with Ca2+ -free medium before inducing Ca2+ paradox. These data indicate that alterations in lysosomal enzymes owing to reinstitution of calcium in Ca2+-deprived hearts may occur as a part of cardiac damage and general cellular disintegration.

scholarly journals Specific alterations in levels of mannose 6-phosphorylated glycoproteins in different neuronal ceroid lipofuscinoses

1998 ◽  
Vol 334 (3) ◽  
pp. 547-551 ◽  
Author(s):  
David E. SLEAT ◽  
Istvan SOHAR ◽  
Premila S. PULLARKAT ◽  
Peter LOBEL ◽  
Raju K. PULLARKAT
Keyword(s):  
Lysosomal Enzyme ◽  
Neurodegenerative Disorders ◽  
Enzyme Activities ◽  
Lysosomal Enzymes ◽  
Vesicular Transport ◽  
Cell Types ◽  
Neuronal Ceroid Lipofuscinoses ◽  
Mannose 6 Phosphate ◽  
Normal Controls ◽  
Lysosomal Proteins

Mannose 6-phosphate (Man-6-P) is a carbohydrate modification that is generated on newly synthesized lysosomal proteins. This modification is specifically recognized by two Man-6-P receptors that direct the vesicular transport of the lysosomal enzymes from the Golgi to a prelysosomal compartment. The Man-6-P is rapidly removed in the lysosome of most cell types; however, in neurons the Man-6-P modification persists. In this study we have examined the spectrum of Man-6-P-containing glycoproteins in brain specimens from patients with different neuronal ceroid lipofuscinoses (NCLs), which are progressive neurodegenerative disorders with established links to defects in lysosomal catabolism. We find characteristic alterations in the Man-6-P glycoproteins in specimens from late-infantile (LINCL), juvenile (JNCL) and adult (ANCL) patients. Man-6-P glycoproteins in LINCL patients were similar to controls, with the exception that the band corresponding to CLN2, a recently identified lysosomal enzyme whose deficiency results in this disease, was absent. In an ANCL patient, two Man-6-P glycoproteins were elevated in comparison with normal controls, suggesting that this disease also results from a perturbation in lysosomal hydrolysis. In JNCL, total levels of Man-6-P glycoproteins were 7-fold those of controls. In general this was reflected by increased lysosomal enzyme activities in JNCL but three Man-6-P glycoproteins were elevated to an even greater degree. These are CLN2 and the unidentified proteins that are also highly elevated in the ANCL.

scholarly journals Proteolytische Aktivitäten der lysosomalen Enzyme bei Milchrindern* – 1. Mitteilung: Variation der lysosomalen Enzyme bei Milchkühen

1999 ◽  
Vol 42 (4) ◽  
pp. 321-334
Author(s):  
L. Panicke ◽  
M. Schmidt ◽  
T. Król ◽  
R. Staufenbiel
Keyword(s):  
Dairy Cattle ◽  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Lysosomal Enzymes ◽  
Milk Traits ◽  
Additional Information ◽  
Milk Performance ◽  
Proteolytic Activities ◽  
Fertility Traits ◽  
Daily Milk

Abstract. Titel of the paper: Proteolytic activities of lysosomal enzymes in dairy cattle. I. Variation of lysosomal enzymes in dairy cattle There are no references to be found in the literature dealing with genetic aspects of lysosomal enzyme activities m blood of dairy cows, The used amino peptidases are connected to the proteolysis. 1011 investigated cows showed Variation coefficients of ≈50%, higher than in milk traits In simultaneous samples it reduces to 20–30% similar to daily milk samples The heritability coefficients h2 = 0,10–0,20 is approximately between fertility traits and milk traits The investigation of lysosomal enzyme activities might be limited to plasma. No additional information could be gained using the leukocytes. Changing activities of enzymes in plasma are aqually directed to the milk performance. It may be concluded that the trait spectrum might be reduced to DP-IV, AGR, ALA, AGLD and EL as well especially to protein yield of milk.

Contracture and cell damage in calcium paradox is not caused by lipid peroxidation

1988 ◽  
Vol 66 (8) ◽  
pp. 1087-1091 ◽  
Author(s):  
B. Belluk ◽  
M. Gupta ◽  
P. K. Singal
Keyword(s):  
Lipid Peroxidation ◽  
Structure Function ◽  
Xanthine Oxidase ◽  
Oxygen Radicals ◽  
Cell Damage ◽  
Calcium Paradox ◽  
Rat Hearts ◽  
Malondialdehyde Content ◽  
Perfused Rat Hearts ◽  
Dose Dependent Decrease

The role of oxygen radicals and lipid peroxidation in calcium-paradox injury in isolated perfused rat hearts was studied by examining the effects of mannitol and (or) allopurinol on this phenomenon. Myocardial changes due to calcium paradox were characterized by contractile failure, a rise in resting tension, and cell damage. These changes were also accompanied by increased lipid peroxidation, as indicated by an increase in malondialdehyde content. Mannitol (an effective quencher of hydroxyl radicals) treatment resulted in a dose-dependent decrease in lipid peroxidation but did not affect other changes due to calcium paradox. Allopurinol (an inhibitor of xanthine oxidase) neither affected lipid peroxidation nor modified any of the structure–function changes due to calcium paradox. These data demonstrate the occurrence of lipid peroxidation which, however, may not be involved in the observed structure–function changes due to calcium paradox. It is also suggested that in this experimental model, xanthine oxidase may not be the inducer of oxygen radicals or of lipid peroxidation.

scholarly journals Effect of monensin on intracellular transport and receptor-mediated endocytosis of lysosomal enzymes

1984 ◽  
Vol 217 (3) ◽  
pp. 649-658 ◽  
Author(s):  
R Pohlmann ◽  
S Krüger ◽  
A Hasilik ◽  
K von Figura
Keyword(s):  
Golgi Apparatus ◽  
Lysosomal Enzyme ◽  
Cathepsin D ◽  
Lysosomal Enzymes ◽  
Intracellular Transport ◽  
Human Fibroblasts ◽  
Free Medium ◽  
Intracellular Enzyme ◽  
Cultured Human Fibroblasts ◽  
Monensin A

In cultured human fibroblasts we observed that monensin, a Na+/H+-exchanging ionophore, (i) inhibits mannose 6-phosphate-sensitive endocytosis of a lysosomal enzyme, (ii) enhances secretion of the precursor of cathepsin D, while inhibiting secretion of the precursors of beta-hexosaminidase, (iii) induces secretion of mature beta-hexosaminidase and mature cathepsin D, and (iv) inhibits carbohydrate processing in and proteolytic maturation of the precursors remaining within the cells; this last effect appears to be secondary to an inhibition of the transport of the precursors. If the treated cells are transferred to a monensin-free medium, about half of the accumulated precursors are secreted, and the intracellular enzyme is converted into the mature form. Monensin blocks formation of complex oligosaccharides in lysosomal enzymes. In the presence of monensin, total phosphorylation of glycoproteins is partially inhibited, whereas the secreted glycoproteins are enriched in the phosphorylated species. The suggested inhibition by monensin of the transport within the Golgi apparatus [Tartakoff (1980) Int. Rev. Exp. Pathol. 22, 227-250] may be the cause of some of the effects observed in the present study (iv). Other effects (i, ii) are rather explained by interference by monensin with the acidification in the lysosomal and prelysosomal compartments, which appears to be necessary for the transport of endocytosed and of newly synthesized lysosomal enzymes.

scholarly journals The selective release of phospholipase A2 by resident mouse peritoneal macrophages

1981 ◽  
Vol 200 (2) ◽  
pp. 441-444 ◽  
Author(s):  
P D Wightman ◽  
M E Dahlgren ◽  
P Davies ◽  
R J Bonney
Keyword(s):  
Phospholipase A2 ◽  
Phospholipase C ◽  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Lysosomal Enzymes ◽  
Culture Medium ◽  
Peritoneal Macrophages ◽  
Cellular Activity ◽  
Mouse Peritoneal Macrophages ◽  
Phospholipase A2 Activity

Resident mouse peritoneal macrophages have three phospholipase activities: a phospholipase A2 active at pH 4.5, a Ca2+-dependent phospholipase A2 active at pH 8.5 and a phosphatidylinositol-specific phospholipase C activity. When macrophages are exposed to zymosan in culture, the cellular activity of pH-4.5 phospholipase A2 is diminished in a manner dependent on zymosan concentration and time of exposure, whereas the cellular activities of pH-8.5 phospholipase A2 and phospholipase C remain unchanged. The depletion of pH-4.5 phospholipase A2 activity from the cell is paralleled by a quantitative recovery of this activity in the culture medium in a manner similar to the cellular depletion and extracellular recovery of two lysosomal enzymes. This release is specifically elicited by an inflammatory substance such as zymosan, since macrophages incubated with 6 micrometer latex spheres retain pH-4.5 phospholipase A2 activity and lysosomal enzyme activities intracellularly.

Myocardial cation contents during induction of calcium paradox

1979 ◽  
Vol 237 (6) ◽  
pp. H713-H719 ◽  
Author(s):  
L. E. Alto ◽  
N. S. Dhalla
Keyword(s):  
Driving Force ◽  
Calcium Influx ◽  
Calcium Paradox ◽  
Control Medium ◽  
Free Medium ◽  
Irreversible Damage ◽  
Rat Hearts ◽  
Induced Changes ◽  
Isolated Rat ◽  
Contractile Failure

Myocardial cation contents were measured in isolated rat hearts perfused under various conditions. Reperfusion of Ca2+-deprived hearts produced marked increases in myocardial Ca2+ and Na+ and decreases in Mg2+ and K+ contents. These changes were dependent on the Ca2+ concentration and duration of perfusion during the periods of Ca2+ deprivation and reperfusion. The loss of Ca2+ and K+ contents normally seen after Ca2+-free exposure as well as the reperfusion-induced changes were prevented if the Ca2+-free medium contained low (35 mM) Na+ or was cooled to 21 degrees C. Reperfusion with normal Ca2+, low Na+ medium augmented the increase in myocardial Ca2+ content, while reducing K+ or Mg2+ or increasing Mg2+ in the reperfusion medium had no effect. Addition of verapamil, D600, or propranolol to the reperfusion solution did not alter the reperfusion-induced cation changes observed using control medium. These data suggest that during Ca2+ depletion, the mechanisms responsible for regulating calcium influx are either lost or inactivated, so that reperfusion-induced changes are governed solely by the driving force favoring calcium influx. The occurrence of Ca2+ overload under this condition has been implicated in the irreversible damage to myocardium and contractile failure.

scholarly journals Influence of protein starvation on some lysosomal enzyme activities in blood serum of sheep

2002 ◽  
Vol 45 (1) ◽  
pp. 79-85
Author(s):  
A. Kołątaj ◽  
J. Klewiec ◽  
A. M. Konecka ◽  
A. Jóźwik ◽  
A. Śliwa-Jóźwik
Keyword(s):  
Blood Serum ◽  
Blood Plasma ◽  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Lysosomal Enzymes ◽  
Protein Deprivation ◽  
Protein Starvation ◽  
H Protein ◽  
In Blood Plasma

Abstract. Reactivity of none lysosomal enzymes in blood plasma of sheep has been estimated. After 48 h protein deprivation the activity of BGLU, BGAL, AAP and LAP increased significantly, NAGL and LL activity decreased, EL and KF activity remained unchanged.

scholarly journals Lysosomal Enzymes and Dibutyryl 3', 5'-Adenosine Monophosphate Basic and Clinical Studies on Lysosomal Enzyme Activities in Glioma Tissues and Glial Cells

1975 ◽  
Vol 15pt1 (1) ◽  
pp. 27-33
Author(s):  
Iekado SHIBATA ◽  
Katsuyuki SATO ◽  
Mikio MATSUMOTO ◽  
Nobuyoshi TAKASU ◽  
Sadatsugu NAGASAWA ◽  
...  
Keyword(s):  
Glial Cells ◽  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Clinical Studies ◽  
Lysosomal Enzymes ◽  
Adenosine Monophosphate

scholarly journals A fluorescence staining method for the demonstration and measurement of lysosomal enzyme activities in single cells.

1985 ◽  
Vol 33 (9) ◽  
pp. 965-968 ◽  
Author(s):  
G P Luyten ◽  
A T Hoogeveen ◽  
H Galjaard
Keyword(s):  
Lysosomal Enzyme ◽  
Enzyme Activities ◽  
Lysosomal Enzymes ◽  
Staining Method ◽  
Single Cells ◽  
Human Cells ◽  
Fluorescence Method ◽  
Fluorescence Staining

A cytochemical fluorescence method is described that makes possible simple, rapid, and specific demonstration and measurement of the activities of a wide variety of lysosomal enzymes in single cells using 4-methylumbelliferyl derivatives as substrates. The validity of the method and a number of applications using normal and mutant human cells are presented.

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