acid-phosphatase and Cataract

To examine the lysosomal enzyme activities in the conjunctival tissues of patients with keratoconus.. Tissues collected from 11 patients with keratoconus, eight patients with senile cataract, three patients with Fuchs' corneal dystrophy, and 11 normal control subjects were processed for histochemical staining for two lysosomal hydrolases, acid esterase and acid phosphatase.. The epithelium of all conjunctival specimens stained positively for the two enzymes. The staining in the conjunctival tissues of patients with keratoconus was more prominent than that seen in specimens from either normal control subjects or patients with other diseases.. Our results suggest that the conjunctival epithelium may be altered in keratoconus. Elevation of lysosomal enzyme levels has been demonstrated in the epithelium of corneas with keratoconus, implicating a role of this layer in the disease. The conjunctival abnormality seems to corroborate the corneal epithelial theory. It also adds one dimension to the pathogenesis of keratoconus.

Topics: Acetylesterase; Acid Phosphatase; Adult; Aged; Aged, 80 and over; Cataract; Conjunctiva; Epithelium; Female; Fuchs' Endothelial Dystrophy; Histocytochemistry; Humans; Keratoconus; Male; Middle Aged

The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium) and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium). In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium) and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium). From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

Topics: Acid Phosphatase; Cataract; Epithelium; Humans; Lens, Crystalline; Lipid Peroxidation

Previous cytochemical and biochemical studies have shown an increase in the activity of acid phosphatase and arylsulfatase during the induction of galactose cataracts in rat lenses. It was postulated that these enzymes may be involved in lens fiber degradation observed during cataractogenesis, however, the role of these enzymes in the repair process was not ruled out. The present investigation has evaluated the level of acid phosphatase activity in lenses in which the induction of opacity is inhibited with the aldose reductase inhibitor sorbinil and during the recovery of galactose induced opacity. Sprague-Dawley rats received 50% galactose diet, or galactose diet with sorbinil, or laboratory chow diet. Following 20 days on this diet all rats received lab chow plus 50 mg kg-1 sorbinil (recovery diet). The lenses were removed at desired intervals following the initiation of the above three diets and following the transfer of animals to the recovery diet. Cytochemical localization and biochemical quantitation of acid phosphatase activity were performed with methods previously reported. Most of the enzyme activity was localized within the epithelial cells and superficial cortical fibers. In the epithelial cell layer, the enzyme activity was primarily localized in lysosomes and at extracellular sites near the epithelial cell membrane which abut each other and cortical fibers. In cortical fibers the enzyme activity was observed at various extracellular sites between the cell membranes of neighboring fibers. The effect of sorbinil, if any, and the possible role of acid hydrolases in the repair process during cataract reversal is discussed.

Topics: Acid Phosphatase; Aldehyde Reductase; Animals; Cataract; Female; Galactose; Histocytochemistry; Imidazoles; Imidazolidines; Lens, Crystalline; Lysosomes; Microscopy, Electron; Rats; Rats, Inbred Strains

The influence of X-radiation on acid phosphatase activity in differentiating meridional row cells of rat lens epithelia was examined by ultrastructural cytochemistry. X-ray doses of 10-12 Gy (1000-1200 rads) produced clearly observable nuclear and cytoplasmic damage at 13-19 hr postirradiation. In those cells, acid phosphatase reaction product was associated with much of the electron dense material of fragmented nuclei and various parts of the cytoplasm. In addition, many irradiated cells without observable damage were positive for reaction product. The presence of acid phosphatase activity in these otherwise normal-appearing cells is suggestive of more subtle radiation damage than that observed in the more severely damaged cells.

Topics: Acid Phosphatase; Animals; Cataract; Epithelium; Female; Histocytochemistry; Lens, Crystalline; Liver; Radiation Dosage; Rats; Rats, Inbred Strains

Localization of acid phosphatase activity is described in equatorial segments of four human cataractous lenses, including one lens with equatorial cortical cataract, and three lenses with no significant equatorial opacities. The lenses were removed surgically with a cryoprobe. Enzyme reaction product was confined mostly to epithelial and cortical Golgi complexes and dense bodies, and to cortical smooth endoplasmic reticulum (SER). It also was located in small cortical vacuolar cysts in the lens with equatorial cataract, and intercellularly in a single lens which was devoid of equatorial opacity. In the latter case, intercellular activity was confined mostly to areas showing minimal pathological modification. Evidence is presented that the cortical SER represented GERL. The hypothesis is made that intercellular acid hydrolase activity might play a role in the early stages of human senile cortical cataract development. However, it is recognized that confirmation of this hypothesis will require additional studies involving comparison of both cataractous and normal lenses of various ages, which have been removed by a careful procedure which minimizes the lysis of lens cells.

Topics: Acid Phosphatase; Aged; Cataract; Endoplasmic Reticulum; Histocytochemistry; Humans; Lens, Crystalline; Microscopy, Electron; Tissue Distribution

Lenses from normal Wistar rats and those from a Wistar strain with X-ray-induced cataract mutation were examined electron microscopically for morphological characterization and acid phosphatase (AcPase) localization. Ocular anlages of 11 through 18 days of gestation were included in the study. A late-separating or persistent lens stalk occasionally was seen in the mutant eyes at 13 days of gestation, but never was observed in eyes of normal animals. The first regular morphological lens abnormality, also observed at 13 days, consisted of an accumulation of unelongated fiber cells (fusiform cells) in the posterior of the mutant lens. Ultrastructurally, these cells contained increased amounts of polyribosomes and coagulated proteins, but lacked the microtubules characteristic of elongated fiber cells. Intercellular AcPase activity appeared in the lens epithelium of both strains of rat beginning at 13 days of gestation, but was sparse in the normal strain. Intercellular reaction product attributable to AcPase activity also was noted in persistent lens stalks. In all ages combined, 66% of the mutant lenses, but only 20% of the normal lenses displayed intercellular activity. The Golgi/GERL complex in the apical regions of the lens epithelial cells of both strains contained AcPase reaction product. Reactive coated vesicles assumed to be primary lysosomes were present in nearby cytoplasm or associated with the Golgi/GERL. It is possible that the elevated amounts of hydrolase activity found in the mutant lenses may play a role in the development of the cataract characteristic of this lens.

Topics: Acid Phosphatase; Animals; Cataract; Female; Lens, Crystalline; Male; Microscopy, Electron; Mutation; Pregnancy; Rats; Rats, Inbred Strains

In the present investigation we have examined the presence, distribution and probable role of acid phosphatase in lenses of normal and galactose-fed rats. Acid phosphatase was localized in lenses using two separate cytochemical procedures (Gomori and Barka-Anderson methods) and examined at the ultrastructural level. Both procedures, in general, provided similar sites of acid phosphatase activity, although with the Barka-Anderson method finer and larger amounts of well-defined reaction product were observable at the site of reaction. The reaction product was observed in lenses of both rats fed on regular laboratory chow and galactose-fed rats. The intracellular location of the reaction of this enzyme was primarily in lysosomes and occasionally in the endoplasmic reticulum cisternae. At the extracellular sites, it was near the epithelial cell membranes which abut each other and cortical fibers. However, in the cortical fibers the extracellular localization was at various sites on the entire intercellular space between neighboring fibers. The possible role of hydrolases in the lens tissue is discussed.

Topics: Acid Phosphatase; Animals; Cataract; Dietary Carbohydrates; Female; Galactose; Histocytochemistry; Lens, Crystalline; Microscopy, Electron; Rats; Rats, Inbred Strains

We studied the activity of acid phosphatase in the anterior segment of the eye with pseudoexfoliation histochemically and biochemically. Light and electron microscopic histochemistry revealed lead precipitates indicating acid phosphatase activity in pseudoexfoliative materials. Biochemical assay for acid phosphatase was significantly higher in the aqueous humor of eyes with pseudoexfoliation than in that of cataractous eyes without pseudoexfoliation.

Topics: Acid Phosphatase; Aged; Aqueous Humor; Cataract; Eye Diseases; Histocytochemistry; Humans; Iris; Lens, Crystalline; Lysosomes; Middle Aged

Lenses of cataract-webbed (cw) Peromyscus maniculatus were examined by electron microscopy and compared to age-matched normal deer mouse lenses. Precataractous lenses of offspring of cw/cw matings were examined and compared to early cataract development in the opposite eye of the same animal. The earliest ultrastructural change leading to disturbance of lens transparency was cell fusion and formation of fiber cell syncytia in the posterior subcapsular region. Fiber cells lost their regular hexagonal packing. Small osmiophilic densities on the plasma membrane coincided with many of the sites of cell confluency. Larger osmiophilic whorls were usually localized in ball-and-socket interlocking junctions after the opacity spread. Epithelial cells from the nasal ventral equator migrated to the posterior pole. Later when underlying cortical fibers ruptured, the migrated cells phagocytized lens proteins and incorporated them in acid-phosphatase positive lysosomes. Fiber cells 3 to 20 layers deep in the cortex of normal and cataractous lenses had acid phosphatase reaction product coating the plasma membrane; the possible significance of this finding is discussed. We postulate that this hereditary cataract results from a defect in turnover and control of plasma membrane components.

Topics: Acid Phosphatase; Animals; Cataract; Female; Lens, Crystalline; Male; Mice; Mice, Inbred Strains; Microscopy, Electron; Osmium Tetroxide; Peromyscus

The tissue culture of normal or cataractous lens epithelium shows acid glycoproteins, which are stored in biosynthetic granules or homogeneously distributed in the cytoplasmic matrix. These acid glycoproteins, which are not sensitive to hyaluronidase, are increased in the pathological cells. The cytolysis and the lysosomal activity, which is its cause, are also more pronounced in the cataractous cells.

Topics: Acid Phosphatase; Animals; Cataract; Culture Techniques; Epithelium; Glycoproteins; Histocytochemistry; Humans; Lens, Crystalline; Lysosomes; Rabbits

Chronic treatment of rats with the amphipilic drugs chloroquine and chlorphentermine caused prominent anterior polar cataracts in virtually all rats. The basic pathologic changes underlying these cataracts were: (a) degeneration of anterior polar and sutural endings of cortical lens cells and (b) multilayered proliferation and invasion of epithelial cells into the anterior polar cortex. Ultrastructurally cortical lens cells displayed various patterns of degeneration, finally undergoing complete liquification. Liquified lens substance was phagocytosed by invading epithelial cells. Cortical lens cells and epithelial cells contained numerous lipidosis-like (lamellated) inclusions, which possessed cytochemical acid phosphatase activity. The present drug-induced lenticular alterations are interpreted as the direct or indirect consequences of a drug-induced disturbance of polar lipid metabolism in the lens.

Topics: Acid Phosphatase; Animals; Cataract; Chloroquine; Chlorphentermine; Epithelium; Female; Inclusion Bodies; Lens, Crystalline; Lipidoses; Lysosomes; Male; Phagocytosis; Phentermine; Rats

Topics: Acid Phosphatase; Aging; Animals; Cataract; Endoplasmic Reticulum; Histocytochemistry; Hydrolases; Lens, Crystalline; Microscopy, Electron; Mitochondria; Rats

Topics: Acid Phosphatase; Animals; Cataract; Epithelial Cells; Epithelium; Female; Histocytochemistry; Lens, Crystalline; Rabbits; Radiation Injuries, Experimental; Time Factors; Ubiquinone

Topics: Acid Phosphatase; Adenosine Triphosphatases; Alkaline Phosphatase; Animals; Cataract; Esterases; Glucosephosphate Dehydrogenase; Glucuronidase; Histocytochemistry; L-Lactate Dehydrogenase; Lens, Crystalline; NAD; NADP; Naphthalenes; Oxidoreductases; Phosphoric Monoester Hydrolases; Rabbits; Succinate Dehydrogenase