Lysosomal Acid Hydrolases Research Articles

Selective release of lysosomal hydrolases from phagocytic cells by cytochalasin B.

1. Cytochalasin B (10mug/ml) enhances the release of rabbit polymorphonuclear leucocyte lysosomal acid hydrolases induced by retinol (vitamin A alcohol). 2. This effect is seen at doses of the vitamin that cause selective release of acid hydrolases and those causing more general enzyme release indicated by the loss of lactate dehydrogenase. 3. Cytochalasin B (2-50mug/ml) has no effect on the release of sedimentable acid hydrolases of intact granules obtained from disrupted polymorphonuclear leucocytes. 4. Cytochalasin B (2-10mug/ml) causes a time- and dose-dependent release of mouse peritoneal macrophage acid hydrolases. 5. This effect is selective at all doses of cytochalasin B used, since no release of lactate dehydrogenase, malate dehydrogenase and leucine 2-naphthylamidase was detected. 6. Treatment with cytochalasin B at doses of up to 10mug/ml for as long as 72h did not significantly change the total activities of any of the enzymes measured. 7. The lack of toxicity of cytochalasin B was shown by dye-exclusion tests and its failure to release radioactive colloidal gold stored in secondary lysosomes.

The lysosome: a role in disease.

Increasing interest in elucidating the role of the lysosome in intracellular metabolic economy has resulted in a deeper understanding of some inborn errors of metabolism, as well as a clearer definition of the intracellular vacuolar apparatus and the role of lysosomes in intracellular drug action and possible specific chemotherapeutic actions. The lysosomal system plays a key role in Pompe's disease (glycogenosis type II). The effect of a selective deficiency of lysosomal acid maltase (acid α-glucosidase) on muscle morphology and biochemistry is shown. The activity of other lysosomal acid hydrolases in muscle is significantly increased. Change in intracellular activity and translocation of primary and secondary lysosomes after membrane activation by steroids are discussed, with data showing the intranuclear migration of lysosomal-like particles, suggesting a mechanism for template activation. Lysosomes play a decisive role in initiating nucleocytoplasmic exchange of information, and they may play a role in genetic derepression, with obvious repercussions in normal and abnormal cell growth. The lysosome model in reference to acid hydrolase induction, especially endocytic and phagolysosomal activity, has been examined.

Normal lysosomal enzyme levels in hypertrophied and failing dog hearts

The activity levels of three lysosomal acid hydrolases, acid phosphatase, acid ribonuclease, and cathepsin, were determined in whole homogenates of right and left ventricular myocardium from normal and chronically stressed dog hearts. Stressed hearts were from four dogs with right ventricular hypertrophy and congestive failure induced by progressive constriction of the main pulmonary artery and from four dogs with acquired right ventricular hypertrophy secondary to pulmonary hypertension resulting from infestation with heartworms ( Dirofilaria immitis). Control hearts were from four unoperated and four sham operated normal dogs. No significant differences were found that could be related to myocardial stress.

Isolation and characterization of a rough microsomal fraction from rat kidney that is enriched in lysosomal enzymes.

1. A special population of rough microsomal material (microsomes) rich in lysosomal acid hydrolases was separated by isopycnic centrifugation as a discrete fraction (RM(2)) from the bulk of rough microsomal material in rat kidney because of its greater density. 2. The specific activities of five acid hydrolases in the RM(2) fraction were approximately one-half those of a purified lysosomal (L) fraction and 10- to 30-fold greater than those of an ordinary rough microsomal (RM(1)) fraction. 3. These special rough microsomes have a distinctive ultrastructure and electron-cytochemical properties. Their cisternal content resembles the matrix of lysosomes in that it is electron-dense, osmiophilic and plumbophilic and gives a positive reaction for acid phosphatase activity. 4. Polyacrylamide-gel electrophoresis of soluble proteins from the L fraction resolved nine anionic glycoproteins, most of which exhibit acid hydrolase activities (Goldstone & Koenig, 1970, 1973; Goldstone et al., 1971a). The most anionic glycoprotein is the acidic lipoglycoprotein of the lysosomal matrix (Goldstone et al., 1970). 5. Polyacrylamide-gel electrophoresis of soluble proteins from the RM(2) fraction resolved two cationic glycoproteins with acid hydrolase activities (Goldstone & Koenig, 1973) and an anionic glycoprotein with the same electrophoretic mobility as the lysosomal lipoglycoprotein, but without its lipid constituents or capacity to bind the basic fluorochrome Acridine Orange. These constituents are considered to be the precursors of the lysosomal glycoproteins.

Lysosomal enzyme activities in rat kidney treated with DOCA, especially with reference to renin, cathepsin and beta-glucuronidase.

In the cytoplasmic fraction (C. F.) of rats treated with DOCA plus salt, renal renin activity was already decreased before the development of hypertension and was more suppressed after that of hypertension. Renal cathepsin activity was slightly increased shortly before the development of hypertension and more elevated after that of hypertension. Increased renal β-glucuronidase activity was found after the longer duration of hypertension. Deoxyribonuclease activity was slightly increased in average after the development of hypertension, but not significantly. Ribonuclease and β-glycerophosphatese activities were not increased, rather slightly decreased after the development of hypertension. The percentage of soluble fraction (S1) or supernatant fraction (S2) to cytoplasmic fraction (C. F.) was diminished in both cathepsin and β-glucuronidase activities in rats treated with DOCA plus high salt as compared with that in the controls, but was nearly identical with that in the controls in β-glycerophosphatase activity. The probable role of lysosomal acid hydrolases in hypertensive vascular lesions was discussed.

Lysosomal acid hydrolases in neonatal rat brain.

Journal of NeurobiologyVolume 4, Issue 2 p. 105-115 Article Lysosomal acid hydrolases in neonatal rat brain† Dr. Harold H. Traurig, Corresponding Author Dr. Harold H. Traurig Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 Sanbbatical year scholar from the Department of Anatomy, College of Medicine, University of Kentucky, Lexington, Kentucky 40506.University of Kentucky, Lexington, Kentucky 40506Search for more papers by this authorNancy R Clendenon, Nancy R Clendenon Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210Search for more papers by this authorJames A. Swenberg, James A. Swenberg Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210Search for more papers by this authorNorman Allen, Norman Allen Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210Search for more papers by this author Dr. Harold H. Traurig, Corresponding Author Dr. Harold H. Traurig Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 Sanbbatical year scholar from the Department of Anatomy, College of Medicine, University of Kentucky, Lexington, Kentucky 40506.University of Kentucky, Lexington, Kentucky 40506Search for more papers by this authorNancy R Clendenon, Nancy R Clendenon Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210Search for more papers by this authorJames A. Swenberg, James A. Swenberg Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210Search for more papers by this authorNorman Allen, Norman Allen Division of Neurology, College of Medicine and Department of Veterinary Pathology, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210Search for more papers by this author First published: 1973 https://doi.org/10.1002/neu.480040203Citations: 11 † Presented at the First Annual Meeting of the Society for Neuroscience, Washington, D. C., 1971 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume4, Issue21973Pages 105-115 RelatedInformation

Lysosomal acid hydrolases in primary monolayer cultures derived from neonatal brains exposed transplacentally to ethylnitrosourea.

SummaryThe effect of transplacental exposure of the fetal rat brain to the carcinogen ethylnitrosourea (ENU) on lysosomal acid hydrolase activities in glial cells has been reported. Primary monolayer cultures of brain cells derived from the brains of newborn rats exposed transplacentally to ENU and from unexposed newborn brains were used to provide concentrated samples of glial cells for hydrolase assay. The hydrolases assayed were β-glucuronidase, N-acetyl-β-D-glucosaminidase, arylsulfatase A and B and acid phosphatase and data were expressed as micromoles of substrate hydrolyzed per hour per milligram of protein. Experimental and control cultures were prepared, incubated and assayed contemporaneously and the ratios between treated and control hydrolase activities were used to evaluate the effect of transplacental ENU exposure.Results showed that there was no effect on the activities of the lysosomal acid hydrolases measured in primary monolayer cultures of brain cells derived from newborn rat brains exp...

Colonic mucosal lysosomal enzyme activities in ulcerative colitis.

Optimal assay conditions and kinetic properties of three acid hydrolase activities, acid phosphatase, arylsulfatase, and β-glucuronidase and a non-lysosomal alkaline phosphatase activity, were determined in colon mucosa from 12 normal subjects and compared to mucosa from 5 patients with ulcerative colitis. There were significant decreases in specific activities of arylsulfatase and β-glucuronidase and significant increases in specific activities of acid and alkaline phosphatase in mucosa from patients with ulcerative colitis when compared to data from normals. Abnormal acid hydrolase activities were found in all diseased portions of mucosa studied but were absent in normal specimens from patients with ulcerative colitis. Such changes in acid hydrolase activities could not be attributed to changes in kinetic properties of the enzymes, changes in binding to particulate cellular material, the presence or absence of dissociable inhibitors or stimulators of the several activities or the lymphocytic portion of the inflammatory exudate in the lamina propria. The three acid hydrolase activities appeared to behave in concert from patient to patient. Although mean activities of both acid and alkaline phosphatase increased in diseased mucosa, there was a significant negative correlation between them in individual patients. Coupled with the slight but significantly decreased inhibition of colon mucosal alkaline phosphatase activity in ulcerative colitis specimens byl-phenylalanine, this disordancy suggests different cells were responsible for the changes in acid hydrolase activities and alkaline phosphatase activity. Whereas these changes may be a result of the disease, they are also consistent with a potential pathogenetic role of lysosomal acid hydrolases in ulcerative colitis.

Acid hydrolases in neuronal and glial enriched fractions of rat brain

Fractions enriched in neuronal and glial cells from rat brain were assayed for several lysosomal acid hydrolases, namely, β-galactosidase (β-D-galactoside galactohydrolase, EC 3.2.1.23), β-glucosidase (β-D-glucoside glucohydrolase, EC 3.2.1.21), α-galactosidase (α-D-galactoside galactohydrolase, EC 3.2.1.22), α-mannosidase (α-D-mannoside mannohydrolase, EC 3.2.1.24), N-acetyl-β-glucosaminidase (β-2-acetamido-2-deoxy-D-glucoside acetamidodeoxyglucohydrolase, EC 3.2.1.30), N-acetyl-β-galactosaminidase, acid phosphatase (orthophosphoric monoester phosphohydrolase, EC 3.1.3.2), β-glucuronidase (β-D-glucuronide glucuronohydrolase, EC 3.2.1.31), arylsulfatase (aryl-sulfate sulfohydrolase, EC 3.1.6.1), glucocerebrosidase and galactocerebrosidase. The data do not show any significant difference in the distribution of these activities between the two cell types.

Changes in liver lysosome fragility, erythrocyte membrane stability, and local and systemic lysosomal enzyme levels in adjuvant-induced polyarthritis

Adjuvant-induced polyarthritis in rats is characterized by the development of liver lysosome fragility, and elevated plasma and local hind paw activities of lysosomal acid hydrolases. During the first few days of the disease, there is a marked increase in liver lysosome fragility and a sharp elevation in plasma β-glucuronidase and acid phosphatase. Commencing on day 4, both liver lysosome fragility and plasma levels of acid hydrolases decrease. Liver lysosome fragility and plasma acid hydrolases again increase on day 9 and continue to rise. Between days 4 and 9, when liver lysosomes appear to be stabilized and plasma levels of acid hydrolases are near control values, the onset of erythrocyte membrane stabilization occurs which endures throughout the disease. Acid phosphatase activity in the injected hind paw increases immediately after induction of polyarthritis as does the swelling, whereas enzyme activity in and swelling of the contralateral hind paw increase 9 or 10 days later. Paramethasone, phenylbutazone and indomethacin, administered orally for various periods of time, attenuated the swelling of primary and secondary lesions and reduced the severity of the biochemical lesions examined.

The effect of p-chloromercuriophenylsulfonate on skin fibroblast acid hydrolases

The inhibition by a sulfhydryl binding reagent, p-chloromercuriophenylsulfonate (pCl MPS) on 9 different “lysosomal acid hydrolases” from skin fibroblasts were investigated. β -Galactosidase was 90% inhibited at 4 × 10 −7M concentration, while α mannosidase was unaffected at 10 −2M concentration.

RELEASE OF LYSOSOMAL HYDROLASES AFTER ISCHEMIA IN DOG HEART

Release of lysosomal acid hydrolases from dog cardiac muscle after cell damage may precede final cellular destruction. An in vivo experiment was designed to study the effects of acute myocardial ischemia on the integrity of the lysosomal particles. The left coronary artery was ligated and the animals were sacrificed at 2, 6, 24, and48 hrs. Aliquots were homogenized and separated by ultracentrifugation into supernatant (S-fraction), large granule (L-fraction) and nuclear fraction (N-fraction).Sequential arterial and coronary sinus samples, the total homogenate and its fractions (S, L and N) were assayed for the activities of cathepsin (3.4.4.23), β-glucuronidase (3.2.1.31), acid phosphatase (3.1.3.2) and cytochrome oxidase (1.9.3.1). There was a steady fall in total homogenate activity for these enzymes within 2 hrs, and the activities reached into half of intact right ventricle in the same heart at 48 hrs.Cathepsin, acid phosphatase and cytochrome oxidase activity decreased in all fractions except the S-fraction of cytochrome oxidase. The latter was the only fraction in which the activity increased after ischemia.Serum acid hydrolases, GOT and LDH titers remained elevated and varied reciprocally with their concentration in total homogenate and especially in S-fraction.The study demonstrates myocardial lysosomal and mitochondrial enzyme activity which is complex and selective retention of enzymes.Finally we demonstrated that the same situation in serum enzyme activities of human acute myocardial infarct, and that emphasized an importance of the knowledge of lysosomal concept concerning with ischemia and cell damage from a point of clinical pathology.

Ozone effect on lysosomal hydrolases of aolveolar macrophages in vitro

Previous studies have shown that ozone in low concentration in vivo depresses the activity of alveolar macrophage acid phosphatase, lysozyme, and β-glucuronidase. In the present studies, rabbit alveolar macrophages were held in tissue culture as a monolayer and were exposed to various concentrations of ozone when covered by only a film of tissue culture media. This approach eliminated recovery of a mixed population of cells from the lung and possible influx of macrophages in response to the noxious agent. Ozone in moderately low concentration, 2 ppm, depressed the activity of macrophage lysosomal acid hydrolases. There was slight accumulation of enzyme in extracellular media during and after three hour exposure to ozone. Hydrolase depression effect was eliminated when the culture media contained sulfhydryl donating reagents—glutathione and cysteine. This may offer a clue to a mechanism of ozone toxicity.

Ozone Effect on Lysosomal Hydrolases of Alveolar Macrophages in Vitro

Previous studies have shown that ozone in low concentration in vivo depresses the activity of alveolar macrophage acid phosphatase, lysozyme, and β-glucuronidase. In the present studies, rabbit alveolar macrophages were held in tissue culture as a monolayer and were exposed to various concentrations of ozone when covered by only a film of tissue culture media. This approach eliminated recovery of a mixed population of cells from the lung and possible influx of macrophages in response to the noxious agent. Ozone in moderately low concentration, 2 ppm, depressed the activity of macrophage lysosomal acid hydrolases. There was slight accumulation of enzyme in extracellular media during and after three hour exposure to ozone. Hydrolase depression effect was eliminated when the culture media contained sulfhydryl donating reagents—glutathione and cysteine. This may offer a clue to a mechanism of ozone toxicity.

Proteolytic enzymes in sea urchin eggs: characterization, localization and activity before and after fertilization.

AbstractThe pH versus proteinase activity curve (casein or hemoglobin plus urea substrate) for homogenates of unfertilized Lytechinus eggs reveals two regions of maximum activity: one between pH 3.5 and 4.3, and another of far greater magnitude from pH 8.0 to 11.0. The two classes of proteinases can be separated on a sucrose density gradient. Both the acid and alkaline proteinases in homogenates prepared in isotonic monovalent salt solutions are remarkably stable at pH 7.4 and 0°C. Using synthetic peptide substrates, an enzyme with the specific esterase activity of chymotrypsin was demonstrated; this enzyme accounts for the major part of the proteinase activity at alkaline pH. In addition, an enzyme with specific esterase activity of trypsin was shown to be present, but of low activity. The proteinase activity at acid pH is largely due to an enzyme resembling cathepsin D. The data also suggest the presence of cathepsin B and cathepsin IV (or catheptic carboxypeptidase).When eggs are homogenized in isotonic NaCl plus KCl at pH 7.4, 0.02 M tris buffer at 0°C, all of the alkaline proteinase, and 85–90% of the acid proteinase activity is sedimented at 10,000 g. The presence of any proteinase activity in the supernatant phase represents an artifact of the preparative procedures used. The granules which possess the proteinase activity are contained entirely in the yolk fractions; and the acid proteinase is contained in a population of granules which sediment more readily than those which contain the alkaline proteinase. The acid proteinase resembles the lysosomal acid hydrolases in that it is readily released from the particulates; in contrast, the alkaline proteinase is bound relatively firmly.In contradistinction to reports in the literature, no changes in proteinase activity nor intracellular distribution could be detected following fertilization.

FURTHER BIOCHEMICAL AND MORPHOLOGICAL STUDIES OF GRANULE FRACTIONS FROM RABBIT HETEROPHIL LEUKOCYTES

Fractionation of rabbit heterophil leukocyte homogenates by isopycnic centrifugation as well as by zonal sedimentation has helped to characterize further the particulate components of these cells. Four classes have been identified: (A) Large (0.5-0.8 microm) and dense (1.26) azurophil or primary granules, containing all the myeloperoxidase, one-third of the lysozyme, and a major proportion of the lysosomal acid hydrolase activities of the cells. (B) Smaller (0.25-0.40 microm) and less dense (1.23) specific or secondary granules, containing 90% of the alkaline phosphatase and the remainder of the lysozyme activities, but very little if any acid hydrolases. (C) Particles of low density (1.20), containing the remainder of the lysosomal acid hydrolases. This fraction was heterogeneous, but showed abundant small rod- or dumbbell-shaped particles of moderate electron opacity, surrounded by a single membrane (tertiary granules?). The possible origin of these lysosomes from contaminating macrophages could not be ruled out but appeared unlikely. (D) Slowly sedimenting material of very low density (1.14), made up of large, empty vesicular membrane structures, and containing 10% of the alkaline phosphatase, and all of a thiol-dependent acid p-nitrophenyl phosphatase, an enzyme clearly different from the lysosomal acid phosphatase.

The influence of the mode of nutrition on the digestive system of Ochromonas malhamensis.

The intracellular distribution and level of acid hydrolases in Ochromonas malhamensis were studied in cells grown osmotrophically in a defined medium, in a carbon-free starvation medium, and during phagotrophy in each of these media. By cytochemical techniques, little enzymic reaction product was observed in the vacuoles of osmotrophic cells grown in the defined medium. Starved cells, however, contained autophagic vacuoles and cannibalized other Ochromonas cells. Dense enzymic reaction product was observed in the digestive vacuoles and in the Golgi cisternae of these starved cells. Moreover, starved cells and cells grown in a nutritionally complete medium ingested Escherichia coli which appeared in digestive vacuoles containing enzymic reaction product. Biochemical assays for lysosomal acid phosphatase (E.C. 3.1.3.2 orthophosphoric monoester phosphohydrolase) and acid ribonuclease (E.C. 2.7.7.16 ribonucleate nucleotido-2'-transferase) were done on Ochromonas cultures in the same experimental treatments and under identical assay conditions as the cytochemical study. During starvation, the acid hydrolase specific activities were consistently twice those found in cells grown in an osmotrophic complete medium. Ochromonas fed E. coli showed no increase in acid hydrolase specific activity as compared to controls not fed E. coli. The latency of lysosomal acid hydrolases in cells fixed with glutaraldehyde was reduced, suggesting that this fixative increases lysosomal membrane permeability and may release enzymes or their reaction products into the cytoplasmic matrix during cytochemical analysis. This could explain the cytoplasmic staining artifact sometimes observed with glutaraldehyde-fixed cells when studied by the Gomori technique. This study confirms that Ochromonas malhamensis, a phytoflagellate, does produce digestive vacuoles and can ingest bacteria, thereby fulfilling its role as a heterotroph in an aquatic food chain. When Ochromonas is grown in a nutritionally complete osmotrophic medium, phagocytosis causes appearance of acid hydrolases in the digestive vacuoles, whereas the total activity of the enzymes remains unchanged. An organic carbon-free medium strongly stimulates acid hydrolaes activity and causes these enzymes to appear in the digestive vacuoles whether phagocytosis occurs or not.

Studies on the nature and localization of acid phosphatase in normal and lens-regenerating urodele eyes. II. Biochemical assay.

AbstractBiochemical assay of acid phosphatase in normal and lens‐regenerating eyes of the urodele Diemictylus viridescens, using p‐nitrophenyl phosphate as substrate, demonstrates both soluble and lysosomal fractions of the enzyme. While the specific activity of the soluble fraction remains unchanged during lens regeneration, the lysosomal fraction shows four distinct rises in specific activity during the thirty‐day regeneration period studied. These peak activities on the second, eighth, fifteenth, and twenty‐second days post‐lentectomy apparently correspond to lysosomal activity in the processes of wound healing, iris depigmentation, and lens differentiation which occur during urodele lens regeneration. On the basis of biochemical and histochemical studies as well as observations of morphological changes in the urodele eye as lens regeneration proceeds, it is postulated that there is a significant correlation between these morphological changes and the level and localization of the lysosomal acid hydrolases in the tissues in which the changes occur.

P-(acetoxymercuric) aniline diazotate, a reagent for visualizing the naphthol AS-BI product of acid hydrolase action at the level of the light and electron microscope.

Diazotized acetoxymercuric aniline in a postcoupling procedure for β-glucuronidase and acid phosphatase using naphthol AS-BI β-d-glucosiduronic acid and naphthol AS-BI-phosphoric acid respectively as substrates has yielded excellent 2-µ sections from Araldite-embedded specimens for light microscopy and correlating electron micrographs for both enzymes. The reaction of the red pigment product with thiocarbohydrazide is believed to establish a mercury-sulfur linkage which is apparently responsible for the pigment's surviving ethanol dehydration and epoxy embedding. Osmication of the tissue before dehydration appears to increase electron density of the product apparently by either chelation to the pigment product, by reduction of osmium tetroxide or by its decomposition with mercuric sulfide. The two acid hydrolases have been demonstrated within the cisternae of the Golgi and the endoplasmic reticulum and within the nuclear envelope of parenchymal cells of mouse and rat liver. Intracytoplasmic lipid inclusions in the livers of both C57 and C3H starved mice have shown a deposition of reaction product for acid phosphatase, whereas only C57 starved mice have shown a deposition of reaction product for β-glucuronidase. Lipid droplets in the rat preputial gland were sites high for β-glucuronidase, as has previously been demonstrated by two dissimilar techniques. Particularly helpful in evaluating the results of electron microscopy has been the use of physiologic controls as, for example, by comparison of findings made with the "high" tissue β-glucuronidase strain, C57, versus those of the "low" tissue β-glucuronidase strain, C3H. Localization of electron-dense product in lysosomes was clear, but not all of this can be attributed unequivocally to enzyme-produced density. The limitations of the technique and the question of nonspecific uptake of diazotized mercuric aniline are discussed. The findings for both hydrolases support the concept of the dual localization of acid hydrolases in lysosomes and in endoplasmic reticulum.

Fine-needle Aspiration Biopsy of the Liver in Healthy Adults Activity of Lysosomal Acid Hydrolases

Summary. The activity of five lysosomal acid hydrolases, β-galactosidase, β-acetylglucosaminidase, β-glucuronidase, acid phosphatase and α-mannosidase, was measured in liver biopsy specimens, obtained with the fine-needle aspiration technique from 24 carefully selected, strictly normal adults. Higher activities were noted than earlier described in less strictly normal controls.