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Biomedical subjects

G E Hook

Publications and source records attributed to G E Hook.

At least 55 records · Page 3Linked to original sources
PubMed1987

The differentiation capacity of Clara cells isolated from the lungs of rabbits.

The purpose of our studies was to determine the growth and differentiation potential of Clara cells isolated from rabbit lungs. The Clara cell preparations were enriched (80 to 85%) by density gradient-elutriation procedures and then were inoculated into rat tracheas denuded of their own epithelium. These tracheas then were transplanted subcutaneously on the backs of nude mice. For purposes of comparison, other denuded tracheas were inoculated with mixed epithelial cells obtained from rabbit tracheas by enzymatic procedures. Control tracheas were inoculated with cell-free media. At 2, 4, and 14 weeks after transplantation, the tracheal grafts were removed from the recipient nude mice and examined by light and electron microscopy. Tracheal grafts not receiving cell inocula contained no epithelial lining, and the tracheal lumens were filled with loose connective tissue. Tracheas inoculated with 2 X 10(4) mixed tracheal cells showed a columnar, pseudostratified epithelium composed of five cell types: (a) poorly-differentiated cells, (b) ciliated cells, (c) mucous cells, (d) Clara-like cells, and (e) typical basal cells. A very different epithelium was established in tracheas repopulated with Clara cell isolates. This epithelium, at all time points examined, was cuboidal, single layered (never pseudostratified), and lacked basal cells. The tracheal lumens were lined with ciliated and nonciliated cells. The latter showed typical features of mature Clara cells (i.e., electron dense granules and smooth endoplasmic reticulum). At 14 weeks, the same two cell types were present, and often they were located on ridges and furrows of the tracheal walls. Mixed tracheal cells inoculated into denuded tracheas gave rise to a normal-appearing pseudostratified mucociliary epithelium, whereas the Clara cells inoculated under identical conditions gave rise to a low cuboidal epithelium resembling that seen in normal bronchioles. Establishment of these two types of epithelial linings occurred in the presence of the same mesenchymal components. Thus, we conclude that Clara cells have considerable self-renewal capacity, and their differentiation potential appears to be quite narrow.

Animals↗
PubMed1986

Separation of pulmonary surfactant phospholipids by high-performance liquid chromatography.

The seven major phospholipid classes of pulmonary surfactant were cleanly separated within 45 min by high-performance liquid chromatography (HPLC) on microparticulate silica (5 microns). Phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, phosphatidyl-ethanolamine, and phosphatidylcholine (PC) were separated with an isocratic mobile phase of acetonitrile--85% phosphoric acid (99:1). Lysophosphatidylcholine and sphingomyelin were subsequently eluted by changing the composition of the mobile phase to acetonitrile--methanol--85% phosphoric acid (97:2:1). Phospholipids were detected by ultraviolet absorbance at 203 nm and were quantitated by integration of peaks. When integrator counts were corrected by using calibration curves obtained from chromatograms of commercial phospholipids and surfactant-derived PC, the HPLC analysis gave results comparable to those obtained by thin-layer chromatography.

Animals↗
PubMed1986

The relationship between intra- and extra-cellular surfactant phospholipids in the lungs of rabbits and the effects of silica-induced lung injury.

Extensive homogenization of lung tissue by nitrogen decompression in a Parr disruption bomb increased by 5-fold the yields of low-density phospholipid (d = 1.06) achieved by other methods. This intracellular phospholipid preparation was high in phosphatidylcholines (84.3%), particularly disaturated phosphatidylcholine (51.2%). On the basis of its low density, composition, and morphological appearance, we concluded that this phospholipid was derived from the intracellular compartment of pulmonary surfactant. We examined the relationship between intra- and extra-cellular surfactant pools according to age, gender and silica-induced pulmonary injury. In normal animals the intracellular pool of surfactant phospholipids increased from 1.54 +/- 0.14 mg at 1 day after birth to 62.30 +/- 4.50 mg per pair of lungs after 31 months, and over the same time period the extracellular pool increased from 1.04 +/- 0.15 mg to 27.45 +/- 2.30 mg per pair of lungs. The ratio between the extracellular and intracellular pools of surfactant increased from 1.50 +/- 0.19 at 1 day after birth to 2.28 +/- 0.23 after 31 months of age. The ratio between the two pools was not influenced by gender, but was changed by the intratracheal injection of silica into the lungs. Intratracheal injection of silica dust increased the levels of surfactant in both compartments, but not to the same extent, indicating that the ratio between the pools could be changed by toxic materials. These data suggest the existence of a size relationship between the intra- and the extra-cellular pools of surfactant, a relationship which implies a common regulatory mechanism that can be disturbed during pulmonary injury.

Age Factors↗
PubMed1986

Effects of silica on the composition of the pulmonary extracellular lining.

The effects of intratracheally injected silica on lung weights and on alveolar macrophages, polymorphonuclear leukocytes, phospholipid, protein, N-acetyl-beta-glucosaminidase, and alkaline phosphatase of the extracellular lining of rat lungs were studied as functions of dose and time. All of these parameters increased with time up to 12 days after a single injection of silica (200 mg/kg) and showed a dose dependence in their responses. Extracellular soluble protein increased 19.8-fold from 1.9 to 37.6 mg/pair of lungs. The composition of the extracellular soluble protein was very similar to that found in normal lungs as determined with two-dimensional-polyacrylamide gel electrophoresis. Although most of the soluble proteins in lavage effluents were similar to those found in serum, several serum proteins were absent, indicating that the selectivity of the lungs for certain serum proteins was maintained after treatment with silica. Increases in extracellular soluble proteins could not be accounted for by damage to the blood/air barrier. Extracellular phospholipid increased 12.1-fold from 1.74 to 21.1 mg/pair of lungs. The phosphatidylcholine content of this phospholipid resembled that of normal pulmonary surfactant but was different from that in free cells lavaged from the lungs of control and silica-treated rats. Increases in extracellular phospholipid were probably due to silica effects on the surfactant system and not to destruction of or release by free cells in the alveoli. N-Acetyl-beta-glucosaminidase and alkaline phosphatase increased approximately 33- and 6-fold, respectively, in response to silica. The number of alveolar macrophages and polymorphonuclear leukocytes increased 1.5- and 75-fold, respectively. Calculation of partial correlations revealed statistically significant relationships among extracellular phospholipids, soluble proteins, and the two hydrolytic enzymes, suggesting that these components were being released into the lung lining from a common source or by a common mechanism.

Acetylglucosaminidase↗
PubMed1986

Induction of intra- and extra-cellular phospholipids in the lungs of rats exposed to silica.

Intracellular and extracellular compartments of phospholipids in the lungs of rats were examined 28 days after intratracheal injection of silica (200 mg/kg). All compartments containing phospholipids were elevated, but the largest increases were seen in the intracellular and extracellular pulmonary surfactant. Intracellular pulmonary surfactant increased 123-fold from 1.18 +/- 0.65 to 144.9 +/- 53.8 and the extracellular surfactant increased 22-fold from 1.17 +/- 0.04 to 25.1 +/- 7.1 mg per pair of rat lungs respectively. The phospholipid composition of intracellular and extracellular surfactant did not change in response to silica, except for an almost 2-fold increase in the percentage of total phosphatidylinositol in both compartments. The phospholipid content of the lungs increased from 24.9 +/- 4.6 to 268.6 +/- 20.8 mg, with the intracellular and extracellular surfactant accounting for 59.1 and 24.6% of this total increase respectively. These data demonstrate that the major increases in the phospholipid content of the lungs induced by silica is associated with the pulmonary-surfactant system.

Animals↗
PubMed1986

Biosynthesis and release of proteins by isolated pulmonary Clara cells.

The major proteins synthesized and released by Clara cells were identified and compared with those synthesized and released by mixed lung cells. Highly purified Clara cells (85.9 +/- 2.4%) and mixed lung cells (Clara cells 4%, Type II cells 33%, granulocytes 18%, macrophages 2.7%, ciliated cells 1.2%) were isolated from rabbit lungs, incubated with Ham's F12 medium in collagen/fibronectin-coated plastic culture dishes in the presence of 35S-methionine for periods of 4 and 18 hrs. Radiolabelled proteins were isolated from the cells and from the culture medium, electrophoresed on polyacrylamide gels in the presence of SDS under reducing conditions, and then autoradiographed. After 4 and 18 hr of incubation of the Clara cells the major radiolabelled cell-associated proteins were those with molecular weights of 6, 48, and 180 Kd. The major radiolabelled proteins released by Clara cells into the medium after 4 hrs of incubation had molecular weights of 6, 48, and 180 Kd, accounting for 42, 16, and 10%, respectively, of the total extracellular protein-associated radioactivity. After 18 hr of incubation the 6 and 48 Kd proteins represented 30 and 18% of the total released radioactivity, and the relative amount of the 180 Kd protein had decreased to 3%. With the mixed lung cells, the major proteins released into the medium had molecular weights of 6 and 48 Kd. Under nonreducing conditions the 6 Kd protein released by Clara cells had an apparent molecular weight of 12 Kd. Labelling isolated Clara cells with a mixture of 14C-amino acids also identified this low molecular weight protein as the major secretory product of the Clara cell. The 6 Kd protein did not label when the cells were incubated with 14C-glucosamine indicating that it was not a glycoprotein. These data demonstrate the release of several proteins from isolated Clara cells but the major protein had a molecular weight of 6 Kd.

Amino Acids↗
PubMed1986

Silica-induced hypertrophy of type II cells in the lungs of rats.

Several investigators have reported the appearance of hypertrophic type II cells in the lungs of silica-treated rats. The purpose of this study was to isolate and characterize these hypertrophic type II cells. Lungs were digested with trypsin and the released cells were separated by using a flow gradient during centrifugal elutriation. Type II cells from control lungs were distributed in the flow gradient as a single population, whereas type II cells from the lungs of silica-treated rats had a bimodal distribution suggesting the presence of two distinct populations of type II cells; one of these populations appeared hypertrophic (type IIB) and the other appeared normal (type II cells; one of these populations appeared hypertrophic (type IIB) and the other appeared normal (type IIA). These two populations of type II cells from silica-treated rats differed significantly in cell size and their lamellar body content. The mean volume of type IIA and type IIB cells was 350 +/- 38 micron 3 and 523 +/- 29 micron 3, respectively. The mean number of lamellar bodies in type IIA and type IIB cells was 77 +/- 53 and 131 +/- 84 per cell, respectively. The mean volume of lamellar bodies was 0.39 +/- 0.09 micron 3 in type IIA cells and 0.66 +/- 0.10 micron 3 in type IIB cells. Type IIA cells were not significantly different from type II cells from the lungs of untreated rats. The distribution of type II cells from silica-treated lungs was such that 2 weeks after a single intratracheal injection of silica (10 mg/rat) type IIB cells accounted for 39.2 +/- 6.4% of the total type II cells recovered after centrifugal elutriation. The general morphological appearance of the isolated type IIA and type IIB cells was similar to that observed in type II cells isolated from untreated rats. These data indicate that hypertrophic type II cells may be isolated from the lungs of silica-treated rats and separated from normal type II cells thus allowing the role of these unusual type II cells in lung injury and repair to be investigated.

Alkaline Phosphatase↗
PubMed1986

Dissolution and reassembly of tubular myelin-like multilamellated structures from the lungs of patients with pulmonary alveolar proteinosis.

Tubular myelin-like multilamellated structures that accumulate in the alveoli of patients with pulmonary alveolar proteinosis are a characteristic manifestation of the disease. These multilamellated structures appear to be an abnormal form of tubular myelin consisting of phospholipid bilayers separated from each other by amorphous proteinaceous material. Treatment of tubular myelin-like multilamellated structures with 10% N-acetylcysteine in aqueous solution resulted in the dissolution and extraction of the intermembranous amorphous material. Extracts contained three major proteins with molecular weights of 36, 56, and 63 kd under reducing conditions; the 36 kd protein accounted for 76.6% of the total protein extracted. In the presence of N-acetylcysteine the 36 kd protein coexisted with a high molecular weight aggregate form (molecular weight greater than 4 X 10(6) daltons). Liposomes, prepared from lipids extracted from the insoluble phase of lavage effluents from the lungs of patients, were mixed with N-acetylcysteine-extracted proteins and then were dialyzed exhaustively against 0.9% NaCl at 37 degrees C. Examination of the precipitated material by electron microscopy revealed the presence of tubular myelin-like multilamellated structures ultrastructurally indistinguishable from those found in the alveoli of patients with pulmonary alveolar proteinosis. Tubular myelin-like multilamellated structures were also formed in large amounts when protein from the lungs of patients with pulmonary alveolar proteinosis was mixed with liposomes prepared from normal human lung surfactant. Tubular myelin-like multilamellated structures were formed with lipids from rabbit liver microsomes or brain homogenates to only a very small degree. Proteins extracted from pulmonary surfactant from the lungs of normal rabbits together with phospholipids extracted from the same source formed a few tubular myelin-like multilamellated structures in which square tubules were detected. These data demonstrate that specific proteins present in the insoluble accumulations from the lungs of patients with pulmonary alveolar proteinosis can spontaneously form tubular myelin-like multilamellated structures under in vitro conditions and in the presence of appropriate lipids.

Animals↗
PubMed1984

Investigation of phospholipids of the pulmonary extracellular lining by electron paramagnetic resonance. The effects of phosphatidylglycerol and unsaturated phosphatidylcholines on the fluidity of dipalmitoyl phosphatidylcholine.

The membranous structures of the pulmonary extracellular lining were removed from the lungs of rabbits by pulmonary lavage and isolated by differential centrifugation. This membranous fraction contained 93% of the total extracellular phospholipids present in lavage effluents and consisted of membranous vesicles, membrane fragments, tubular myelin and secreted lamellar bodies. The fraction was rich in phosphatidylcholine (79.4%) containing 85.2% palmitic acid in the 1-position and 57.4% palmitic acid in the 2-position. Phosphatidylglycerol was the next most abundant phospholipid, accounting for 9.4% of the total. E.p.r. spectra, obtained by using 5-doxylmethylstearate as a probe, showed that the extracellular phospholipids of the pulmonary lining were organized into structures which were much more fluid than erythrocyte-ghost membranes. The fluidity of phosphatidylcholine isolated from the membranous fraction was similar to that of the fraction itself, indicating that the minor phospholipids had very little influence on the fluidity of the major phospholipid. At physiological temperature, the fluidity of dipalmitoyl phosphatidylcholine was relatively low, but could be markedly increased by the presence of 1-palmitoyl-2-oleoyl phosphatidylcholine or phosphatidylglycerol (10%). Protein present in the extracellular phospholipid fraction did not affect the fluidity of the fraction. These studies indicate that the unsaturated phosphatidylcholines could play a major role in determining the fluidity of the important surface-tension-lowering phospholipids such as dipalmitoyl phosphatidylcholine.

Animals↗
PubMed1984

The pulmonary extracellular lining.

The extracellular lining of the lungs is reviewed. The pulmonary extracellular lining is a complex mixture of phospholipids, proteins and carbohydrates which is absolutely essential for the maintenance of normal pulmonary functions such as gas exchange. Without the lining the lungs would collapse. Alterations in the pulmonary extracellular lining may underlie some disease conditions induced by toxic agents, especially those which interfere with the formation of pulmonary surfactant. The extracellular lining could be used to detect and monitor damage and disease caused by agents toxic to the lungs. The lining contains many hydrolytic enzymes which may act to detoxify certain toxic agents such as those which contain ester groups. The pulmonary extracellular lining could play a significant role mediating the toxic action of inhaled agents as well as the removal of those agents from the lungs.

Animals↗
PubMed1984

Multilamelled structures from the lungs of patients with pulmonary alveolar proteinosis.

Multilamellated structures (MS), which accumulate in the lungs of patients with pulmonary alveolar proteinosis, were examined under the electron microscope. MS, in general, consisted of alternating light and dark lamellae arranged concentrically about membranous vesicles or electron-dense bodies. The darker osmiophilic lamellae consisted of trilaminar membranes 80 to 100 A thick, and the lighter lamellae, which varied from 150 to 300 A in width, appeared amorphous. MS made up 42.6 +/- 12.4% (n = 4) of the total particulate volume present in the pulmonary lavage effluents. MS resembled tubular myelin structures from the lungs of patients, although these latter structures accounted for only 1.6 +/- 2.3% (n = 4) of the total particulate volume. Abnormalities, such as polygonal tubules, irregular tubule dimensions, and large size potential, indicated that tubular myelin structures in the lungs of patients were variable in structure. MS appear to be a form of tubular myelin structure. MS were treated with a variety of disruptive agents and then examined under the electron microscope. Information was obtained about the composition of the MS and the intermolecular forces involved in their three-dimensional organization. Extraction of the MS with acetone or treatment of the structures with phospholipase c resulted in loss of membranes from the structures without a concomitant loss of the intermembranous amorphous material, indicating that phospholipids were a major membrane component. Analysis of phospholipids in the acetone extracts of the MS revealed that the membranes consisted of 45% phosphatidylcholine and that the major fatty acid of the phosphatidylcholine was palmitate (76%). The amorphous material of the intermembranous spaces consisted primarily of protein, since it was destroyed by the proteases trypsin and pronase without loss of the membranes. Reducing agents such as mercaptoethanol and dithiothreitol were disruptive, indicating the importance of disulfide bridges between the protein constituents in maintaining the integrity of the MS. The significance of hydrophobic interactions between the protein constituents was demonstrated by the disruptive action of chaotropic agents according to the sequence KSCN greater than KI greater than KCl. These data indicate that MS consist of phospholipid membranes organized in a protein matrix maintained by intermolecular disulfide bridges and hydrophobic interactions.

Biological Products↗
PubMed1984

Pulmonary macrophage accumulation and asbestos-induced lesions at sites of fiber deposition.

Inhaled chrysotile asbestos fibers are deposited at alveolar duct bifurcations and subsequently are phagocytized there by pulmonary macrophages. The characteristics of the rapid macrophage response at alveolar duct bifurcations following asbestos inhalation has been further evaluated. Significant numbers of pulmonary macrophages accumulated at sites of asbestos deposition within 48 h after a 1-h exposure, whereas duct surfaces of sham-exposed animals were essentially devoid of macrophages. The influx of macrophages was associated with a significantly increased bifurcation tissue area (p less than 0.025), and this alteration persisted for at least 1 month. Two thirds of the accumulated macrophages from alveolar duct bifurcations could be removed by bronchoalveolar lavage. Macrophages recovered by lavage had significant changes (p less than 0.01) in their morphology and in their phagocytic and chemotactic capacities. These cellular alterations could play a role in the pathogenesis of asbestos-related lung disease.

Animals↗
PubMed1983

Induction by morpholine of lysosomal alpha-mannosidase and acid phosphatase in rabbit alveolar macrophages in vivo and in vitro.

alpha-Mannosidase and acid phosphatase were induced in alveolar macrophages from the lungs of rabbits following exposure to morpholine. The induction was observed after inhalation of morpholine vapor or when macrophages were cultured in the presence of morpholine. Lysosomal hydrolases were not induced uniformly. In vivo, maximum induction of alpha-mannosidase and acid phosphatase in female rabbits was 1.7-fold and 2-fold, respectively, and in male rabbits, 3-fold and unchanged, respectively. In vitro, maximum hydrolase induction of alpha-mannosidase and acid phosphatase in macrophages from male rabbits was 1.4-fold and 1.3-fold, respectively, and from female rabbits, 1.3-fold and 1.5-fold, respectively. The induction of acid hydrolases in vitro was rapid, reaching a maximum within 4 hr in alveolar macrophages from male rabbits and within 8 hr in those from females. The induction was dose dependent. This study indicates that the lysosomal enzyme system of the alveolar macrophage may be stimulated by a low molecular weight xenobiotic.

Acid Phosphatase↗
PubMed1983

Isolation and characterization of rabbit lung lamellar bodies.

A method has been devised for the isolation of a highly purified preparation of lamellar bodies from rabbit lung. The purity of the preparation was confirmed by electron microscopy, marker enzymes, phospholipid composition, and isopycnic centrifugation on continuous density sucrose gradients. Contamination of the lamellar bodies by such subcellular components as mitochondria, nuclei, lysosomes and plasma membranes could be excluded; however, reduced nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome c reductase, an enzyme specific for the endoplasmic reticulum components was a persistent contaminant in the preparation of the isolated lamellar bodies. When the lamellar bodies were subject to isopycnic centrifugation, all of the NADPH cytochrome c reductase activity was associated with the lamellar bodies in the low density peak; no reductase activity could be detected in the region of the density gradient demonstrated to localize microsomes. Use of 3H-radiolabeled microsomes confirmed that all of the NADPH cytochrome c reductase activity present in the lamellar body preparations could be accounted for by microsomal contamination. When lamellar bodies or liposomal membranes synthesized from the total phospholipid fraction of lamellar bodies were analyzed by the electron paramagnetic resonance probe, 5-dioxyl-methylstearate, they exhibited a high degree of fluidity at physiological temperature. This was in contrast to the low fluidity of liposomal membranes composed of pure dipalmitoylphosphatidylcholine, the major component (50%) of rabbit lamellar body phospholipids. Furthermore, the major temperature-dependent phase transition in lamellar body membranes occurred at a different temperature (30.5 degrees C) from that of dipalmitoyl-phosphatidylcholine (41.0 degrees C). It is clear, therefore, that the membrane fluidity of lamellar bodies must be highly influenced by the minor lipid component.

Animals↗
PubMed1982

Production of low molecular weight cadmium-binding proteins in rabbit lung following exposure to cadmium chloride.

Low molecular weight cadmium-binding proteins were studed in lung tissue from rabbits exposed to aerosols of CdCl2. Lungs obtained from animals exposed by inhalation to aerosols of 800 or 1600 micrograms/m3 CdCl2 for 2-hr periods/day, every other day for a 5-day period, were found to contain at least three low molecular weight cadmium-binding proteins, two of which were similar electrophoretically and spectrally to rabbit liver metallothionein. The third protein(s), which accounted for the majority of the cadmium in the soluble fraction of the tissue, did not bind to an anionic exchange gel and did not appear to be a polymerized form of metallothionein. Translocation studies of lung cadmium suggest a long half-life for cadmium in lung tissue following inhalation exposure, due perhaps to the high affinity of cadmium for specific lung cadmium-binding proteins. A small but significant redistribution of lung cadmium did occur to both kidney and liver tissue with time.

Aerosols↗
PubMed1981

Quantitation of specific proteins in polyacrylamide gels by the elution of Fast Green FCF.

The quantitation of proteins in polyacrylamide gels stained with Fast green FCF has been investigated using a modification of the elution technique originally described by Fenner et al. (Fenner, C., Traut, R.R., Mason, D.T. and Wikman-Coffelt, J. (1975) Anal. Biochem. 63, 595--602) for Coomassie Blue and adapted by Medugorac (Medugorac, I. (1979) Basic Res. Cardiol. 74, 406--416) for use with proteins stained with Fast Green FCF. The elution of dye from stained protein was accomplished using 1.0 M NaOH instead of aqueous pyridine as required by the original method. The primary advantages of our modification are that the time required for protein quantitation has been considerably reduced and the use of toxic organic solvents has been eliminated. We have investigated the applicability of the method of several different proteins and our results indicate: (a) The quantity of Fast Green FCF eluted from specific proteins is proportional to the quantity of protein applied to the gel, but varies for each individual protein. (b) The method allows quantitation over a very wide range of protein (1--800 micrograms). (c) Quantitation of protein is independent of the width of the stained bands as well as acrylamide concentration. (d) The method is applicable to gels of many types including disc, slab and continuous gradient gels. (e) Protein can be estimated from the patterns obtained by two-dimensional polyacrylamide gel electrophoresis. (f) The presence of Triton X-100 in gel and protein sample does not affect quantitation; the method is applicable to gels containing SDS provided that SDS is removed prior to staining. (g) Precipitation of protein with 12.5% TCA following electrophoresis does not interfere with quantitation. (h) The reproducibility of the technique is excellent, with standard deviations being less than 10% of the mean in all cases. This method appears highly versatile but requires appropriate standards for the quantitation of individual proteins.

Animals↗
PubMed1981

Extracellular alkaline phosphatase from alveolar secretions of patients with pulmonary alveolar proteinosis.

Alkaline phosphatases in alveolar secretions from the lungs of patients with pulmonary alveolar proteinosis have been studied. A soluble form of alkaline phosphatase was isolated from the secretions and characterized. The extracellular enzyme had a pH optimum at 9.95; was stimulated by Mg2+, Ni2+, and Mn2+; was inhibited by Zn2+, Be2+, Cu2+, and low concentrations (8 mM) of L-homoarginine and imidazole; and was heat-stable at 55 degrees C. The soluble phosphatase existed primarily as a high molecular weight complex (excluded from Sepharose 4B) and could be dispersed into low molecular weight forms (205 000--285 000) by treatment with n-butanol. Following butanol treatment, the thermostability of the enzyme was markedly decreased but the kinetic properties such as the Km values, activation energies, and responses to various inhibitors were unchanged. The alkaline phosphatase may originate from unusual type 2 cells present in the alveoli of patients with pulmonary alveolar proteinosis.

Alkaline Phosphatase↗