TRANSPORT ADENOSINE TRIPHOSPHATASE CYTOCHEMISTRY II. CYTOCHEMICAL LOCALIZATION OF OUABAIN-SENSITIVE, POTASSIUM-DEPENDENT PHOSPHATASE ACTIVITY IN THE SECRETORY EPITHELIUM OF THE AVIAN SALT GLAND

1972 ◽  
Vol 20 (1) ◽  
pp. 23-38 ◽  
Author(s):  
STEPHEN A. ERNST
Keyword(s):  
Phosphatase Activity ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Salt Gland ◽  
Ultrastructural Localization ◽  
Defined Medium ◽  
Secretory Cells ◽  
Cytochemical Localization ◽  
Fixed Tissue ◽  
Nitrophenyl Phosphate

A cytochemical procedure is described for the ultrastructural localization of K-dependent, ouabain-sensitive nitrophenyl phosphatase activity in avian salt gland. Cryostat sections (50 µ) of paraformaldehyde-fixed tissue were incubated in a kinetically defined medium containing: 5 mM p-nitrophenyl phosphate, 10 mM MgCl2, 10 mM KCl, 100 mM Tris-HCl buffer (pH 8.5 or 9.0) and 20 mM SrCl2 to precipitate hydrolyzed phosphate. After incubation at room temperature, the sections were treated with Pb(NO3)2 to convert SrPi to PbPi precipitates for visualization in the electron microscope. Reaction product was localized on the cytoplasmic side of the secretory cell lateral and basal plasma membranes. Little, if any, reaction product was associated with the apical surfaces of the secretory cells or with endothelial surfaces of capillaries. Appropriate control experiments indicated that deposition of reaction product was dependent on Mg and K and was sensitive to ouabain. Furthermore, nonenzymatic hydrolysis of nitrophenyl phosphate did not occur in the medium, and deposition of artifactually produced precipitates did not resemble deposition of enzymatically produced precipitates. The relationship of this localization to transport adenosine triphosphatase cytochemistry is discussed, and the physiologic implications of the localization for tracing the route of active Na transport in the salt gland are considered.

scholarly journals TRANSPORT ADENOSINE TRIPHOSPHATASE CYTOCHEMISTRY I. BIOCHEMICAL CHARACTERIZATION OF A CYTOCHEMICAL MEDIUM FOR THE ULTRASTRUCTURAL LOCALIZATION OF OUABAIN-SENSITIVE, POTASSIUM-DEPENDENT PHOSPHATASE ACTIVITY IN THE AVIAN SALT GLAND

1972 ◽  
Vol 20 (1) ◽  
pp. 13-22 ◽  
Author(s):  
STEPHEN A. ERNST
Keyword(s):  
Enzymatic Activity ◽  
Adenosine Triphosphatase ◽  
Biochemical Characterization ◽  
Metal Salt ◽  
Salt Gland ◽  
Ultrastructural Localization ◽  
Defined Medium ◽  
Fixed Tissue ◽  
Fold Reduction ◽  
Nitrophenyl Phosphate

The optimal kinetic parameters for the K-dependent, ouabain-sensitive hydrolysis of p-nitrophenyl phosphate by K-nitrophenyl phosphatase, under conditions closely approximating those employed for cytochemistry, were determined in the avian salt gland as a necessary prerequisite for the ultrastructural localization of the enzyme. The enzyme was characterized in 50-µ cryostat sections of paraformaldehyde-fixed tissue, incubated at room temperature in a medium containing 5 mM nitrophenyl phosphate, 10 mM MgCl2, 20 mM SrCl2 and 100 mM Tris-HCl buffer (pH 9.0), either with or without 10 mM KCl. For comparison, parallel assays were conducted in the absence of Sr, the heavy metal salt used to precipitate phosphate for cytochemistry. Enzymatic activity was determined by measuring spectrophotometrically the amount of nitrophenol hydrolyzed. In this system, Sr acts as a pure noncompetitive inhibitor of the enzyme, causing 50% inhibition at 3 mM and 87% at 20 mM. The Km for the enzyme is 4.5 mM. Sr (20 mM) causes an 8-fold reduction in the apparent affinity of the enzyme for Mg but has little effect on K affinity. The sensitivity of the enzyme to ouabain is decreased 50-fold in the presence of 20 mM Sr. The relationship of this enzymatic activity to Na-K-activated adenosine triphosphatase and the application of this defined medium to transport adenosine triphosphatase cytochemistry are discussed.

scholarly journals PRESERVATION OF Na-K-ACTIVATED AND Mg-ACTIVATED ADENOSINE TRIPHOSPHATASE ACTIVITIES OF AVIAN SALT GLAND AND TELEOST GILL WITH FORMALDEHYDE AS FIXATIVE

1970 ◽  
Vol 18 (4) ◽  
pp. 251-263 ◽  
Author(s):  
STEPHEN A. ERNST ◽  
CHARLES W. PHILPOTT
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Electron Microscopic Examination ◽  
Salt Gland ◽  
Chloride Cells ◽  
Secretory Cells ◽  
Salt Glands ◽  
Electron Microscopic ◽  
Fixed Tissue ◽  
Gill Filaments

The effect of glutaraldehyde and formaldehyde fixation on the level of biochemically demonstrable Na-K-adenosine triphosphatase (Na-K-ATPase) and Mg-ATPase of avian salt glands and teleost gill filaments was studied. Sections, 100-200 µ, prepared with the Smith-Farquhar tissue chopper, were fixed for varying periods, homogenized and assayed for ATPase activity. Fixation of salt gland tissue with 0.5% glutaraldehyde for 40-60 min completely inhibited the Na-K-ATPase activity and reduced the level of Mg-ATPase by 85%. In contrast, fixation with 2 or 3% formaldehyde, prepared from paraformaldehyde, for 60-90 min resulted in a loss of only 30% of the Na-K-ATPase activity and 65% of the Mg-ATPase activity. Similar results were obtained with gill filaments. In addition, Na-K-ATPase of formaldehyde-fixed tissue retained an obligatory requirement for Na+ and K+ and was fully sensitive to ouabain. Electron microscopic examination of formaldehyde-fixed tissue, sectioned with either the tissue chopper or in the cryostat and incubated in the Wachstein-Meisel medium, showed excellent morphologic preservation. Reaction product deposition (presumably due to Mg-ATPase) was associated with the extracellular side of the plasma membrane in the secretory cells of the salt gland and over the mitochondrial matrix of chloride cells present in the gill epithelium.

scholarly journals Cytochemical demonstration of sodium, potassium-adenosine triphosphatase by a hemepeptide derivative of ouabain.

1978 ◽  
Vol 26 (12) ◽  
pp. 1042-1052 ◽  
Author(s):  
J E Mazurkiewicz ◽  
F E Hossler ◽  
R J Barrnett
Keyword(s):  
Plasma Membranes ◽  
Salt Gland ◽  
Ultrastructural Localization ◽  
Fixed Tissue ◽  
Sodium Potassium ◽  
Cytochemical Demonstration ◽  
Biological Affinity ◽  
Noncompetitive Inhibitor ◽  
Membrane Components ◽  
Apical Membranes

A cytochemical probe for the ultrastructural localization of the NaKATPase was devised, which utilizes the biological affinity of the noncompetitive inhibitor, ouabain (ouab) to which was coupled a hemepeptide (H11P) which possesses peroxidatic activity. The conjugate, ouab-H11P, had an apparent Ki of approximately 8 x 10(-7) M. When reacted with fixed tissue from the salt gland of osmotically stressed ducklings, the NaKATPase was localized to the basal and lateral infoldings of the plasma membranes of secretory epithelial cells. Reaction product consisted of fine textured deposits distributed in focal patches on the outer aspects of the membrane. Apical membranes were negative, as were intracellular membrane components. Preincubation of tissue with unlabeled ouabain or binding of ouab-H11P in the presence of 10 mM K+, no ATP and no Mg++, resulted in the absence or diminution of reaction product.

scholarly journals PROBLEMS OF SPECIFICITY IN THE USE OF A STRONTIUM CAPTURE TECHNIQUE FOR THE CYTOCHEMICAL LOCALIZATION OF OUABAIN-SENSITIVE, POTASSIUM-DEPENDENT PHOSPHATASE IN MAMMALIAN RENAL TUBULES

1974 ◽  
Vol 22 (12) ◽  
pp. 1163-1168 ◽  
Author(s):  
J. A. FIRTH
Keyword(s):  
Alkaline Phosphatase ◽  
Proximal Tubule ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Distal Tubule ◽  
Renal Tubules ◽  
Cytochemical Localization ◽  
Nitrophenyl Phosphate ◽  
Basal Plasma ◽  
Tubule Cells

The p-nitrophenyl phosphate-strontium procedure for the localization of the phosphatase component of Na-K-activated adenosine triphosphatase was evaluated using rat renal cortex as a test tissue. The results obtained by light microscopy were unexpected in that reaction product was found only on the brush borders of proximal tubule cells; this reaction was ouabain-resistant, K-independent and partially Mg-dependent, but could be completely inhibited by l-tetramisole. Electron microscopy showed that a reaction was also present on the cytoplasmic surfaces of the lateral and basal plasma membranes of the proximal and distal tubule cells. That seen in the distal tubule was sensitive to ouabain but not to l-tetramisole, whereas that in the proximal tubule showed a mixture of ouabain-sensitive and l-tetramisole-sensitive components. It is concluded that the procedure as originally described is not specific, demonstrating alkaline phosphatase as well as Na-K-adenosine triphosphatase, but that this problem may be overcome by the use of an alkaline phosphatase inhibitor.

Biogenesis of Plasma Membranes in Salt Glands of Salt-Stressed Domestic Ducklings: Localization of Acyltransferase Activity

1972 ◽  
Vol 11 (3) ◽  
pp. 855-873
Author(s):  
A. M. LEVINE ◽  
JOAN A. HIGGINS ◽  
R. J. BARRNETT
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Salt Gland ◽  
Secretory Cells ◽  
Salt Glands ◽  
Acyltransferase Activity ◽  
Structural Localization ◽  
Differentiated Cells ◽  
Golgi Membranes

In response to salt water stress there is a marked increase in the plasma membranes of the epithelial secretory cells of the salt glands of domestic ducklings. In the present study, the fine-structural localization of the acyltransferases involved in synthesis of phospholipids has been investigated in this tissue during this increased biogenesis of plasma membranes. The specific activity of the acyltransferases of the salt gland rose in response to salt stress, and this preceded the rapid increase in weight and cellular differentiation. After the weight increase of the gland became established, the specific activity of the acyltransferases declined, but the total activity remained constant. Salt gland tissue fixed in a mixture of glutaraldehyde and formaldehyde retained 35% of the acyltransferase activity of unfixed tissue. Cytochemical studies of the localization of acyltransferase activity in fixed and unfixed salt gland showed reaction product associated only with the lamellar membranes of the Golgi complex. This localization occurred in partially differentiated cells from salt-stressed glands to the greatest extent; and to only a small extent in cells of control tissue from unstressed salt glands. Omission of substrates resulted in absence of reaction product in association with the Golgi membranes. In addition, vesicles having limiting membranes morphologically similar to the plasma membrane occurred between the Golgi region and the plasma membrane in the partially differentiated cells. The phospholipid component of the plasma membrane appears therefore to be synthesized in association with the Golgi membranes and the membrane packaged at this site from which it moves in the form of vesicles to fuse with the pre-existing plasma membrane.

Primary culture of duck salt gland. I. Morphology of confluent cell layers

1985 ◽  
Vol 249 (1) ◽  
pp. C32-C40 ◽  
Author(s):  
R. J. Lowy ◽  
J. H. Schreiber ◽  
D. C. Dawson ◽  
S. A. Ernst
Keyword(s):  
Electron Microscopy ◽  
Primary Culture ◽  
Plasma Membranes ◽  
Freeze Fracture ◽  
Salt Gland ◽  
Direct Access ◽  
Secretory Cells ◽  
Collagen Gels ◽  
Lateral Membrane ◽  
Confluent Cell

Dissociated avian salt gland secretory cells were maintained in primary culture after plating on hydrated collagen gels. When seeded at 3 X 10(6) cells/cm2, confluent cell sheets formed within 2-3 days, whereas cultures seeded at lower densities formed a complex reticulum of cell aggregates, which remained nonconfluent even after 7 days. Scanning electron microscopy showed that the free surface of 3-day confluent cultures consisted of intermixed convex and flattened cell membranes with prominent junctional boundaries and abundant microvilli. Transmission electron microscopy indicated that these cultures were multilayers of 1-4 cells in thickness. The plasma membranes of the superficial cells were polarized into apical and basolateral regions displaying, respectively, microvilli and interdigitating lateral membrane folds. These membrane domains were separated by shallow occluding junctions, which consisted of both single strands and simple net-like arrays in freeze-fracture images. Underlying epithelial cells retained lateral membrane folds and formed desmosomal contacts with superficial and neighboring cells. These cultures, unlike the intact tissue, allow direct access to the apical and basolateral cell surfaces for electrophysiological analysis of transmural active ion transport.

Ultrastructural Localization of NA+-K+ -Atpase in Rabbit Cornea Using 5-Nitroindoxyl Phosphate as Substrate

1977 ◽  
Vol 35 ◽  
pp. 444-445
Author(s):  
K. C. Tsou ◽  
Mahin Khatami
Keyword(s):  
Endothelial Cells ◽  
Comparative Study ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Endothelial Damage ◽  
Previous Method ◽  
New Method ◽  
Rabbit Cornea ◽  
Fixed Tissue ◽  
Nitrophenyl Phosphate

Recently, Leunberger and Novikoff (1) have shown that the endothelial cells are the primary sites of Na+-K+-ATPase, a key mechanism in the control of hydration of cornea. Since this enzyme would be a useful marker for our study of endothelial damage by CO2 laser (2), we have undertaken a comparative study for the localization of this enzyme at ultrastructural level with different methods. In the course of this work we developed a new method with the use of 5-nitroindoxyl phosphate as a synthetic substrate. This new substrate, like p-nitrophenyl phosphate (3), meets the requirements for the demonstration of the K+ activated step of dephosphorylation of ATPase. In addition, it can be used with glutaraldehyde fixed tissue, thereby offering an important advantage over the previous method (3).Rabbit corneas were freshly excised under pentobarbitol anesthesia.

Plasma Membrane Biogenesis

1974 ◽  
Vol 32 ◽  
pp. 312-313
Author(s):  
Russell J. Barrnett
Keyword(s):  
Plasma Membrane ◽  
Trigeminal Nerve ◽  
Salt Gland ◽  
Ultrastructural Localization ◽  
Secretory Cells ◽  
Membrane Biogenesis ◽  
Cell Plasma ◽  
Microsome Fraction ◽  
Myelin Fraction

This report presents two examples of plasma membrane biogenesis in which the synthesis and assembly of components, phospholipid and enzyme proteins, were studies by a combination of biochemistry, cytochemistry and electron microscopy. These were: the proliferation of Schwann cell plasma membrane during the process of myelination of the trigeminal nerve in neonatal rats and amplification of the plasma membrane at the lateral and basal borders of secretory cells of the ducklings' salt gland as a result of salt stress.In the study concerning myelination a method for the ultrastructural localization of acyltransferase activities (the first two steps in phospholipid synthesis) was applied to the developing rat trigeminal nerve. Determination of acyltransferase levels in the nerve indicated that a peak of activity occurs at the 8th day after birth with gradual declines of activity up to 15 days. This peak coincided with the peak of a-glycerophosphate incorporation into phospholipids in the microsome fraction of the nerve: wheras, no incorporation was noted in the myelin fraction.

scholarly journals Calcium ion-dependent p-nitrophenyl phosphate phosphatase activity and calcium ion-dependent adenosine triphosphatase activity from human erythrocyte membranes

1973 ◽  
Vol 136 (1) ◽  
pp. 185-194 ◽  
Author(s):  
Alcides F. Rega ◽  
Donaldo E. Richards ◽  
Patricio J. Garrahan
Keyword(s):  
Cell Membrane ◽  
Phosphatase Activity ◽  
Human Erythrocyte ◽  
Calcium Ion ◽  
Adenosine Triphosphatase ◽  
Erythrocyte Membranes ◽  
Dependent Atpase ◽  
Nitrophenyl Phosphate ◽  
Inner Surface ◽  
Human Erythrocyte Membranes

In the presence of ATP and of Mg2+, human erythrocyte membranes show a phosphatase activity towards p-nitrophenyl phosphate which is activated by low concentrations of Ca2+. The effect of Ca2+ is strongly enhanced if either K+ or Na+ is also present. Activation of the p-nitrophenyl phosphate phosphatase by Ca2+ reaches a half-maximum at about 8μm-Ca2+ and is apparent only when the ion has access to the inner surface of the cell membrane. Ca2+-dependent phosphatase activity can only be observed if ATP is at the inner surface of the cell membrane, and the presence of ATP seems to be absolutely necessary, since either its removal or its replacement by other nucleoside triphosphates abolishes the activating effect of Ca2+. The properties of the (ATP+Ca2+)-dependent phosphatase are very similar to those of the Ca2+-dependent ATPase (adenosine triphosphatase), also present in erythrocyte membranes, which probably is involved in Ca2+ transport in erythrocytes. The similarities suggest that both activities may be properties of the same molecular system. This view is further supported by the fact that p-nitrophenyl phosphate inhibits to a similar extent Ca2+-dependent ATPase activity and ATP-dependent Ca2+ extrusion from erythrocytes.

ULTRASTRUCTURAL LOCALIZATION OF A CHARACTERISTIC ACID PHOSPHATASE IN GRANULES OF RABBIT BASOPHILS

1974 ◽  
Vol 22 (12) ◽  
pp. 1092-1104 ◽  
Author(s):  
ATSUSHI KOMIYAMA ◽  
SAMUEL S. SPICER
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Potential Role ◽  
Strong Acid ◽  
Ultrastructural Localization ◽  
Buffy Coat ◽  
Cytoplasmic Granules ◽  
Nitrophenyl Phosphate ◽  
Tris Maleate

Bone marrow basophils incubated in Gomori medium at pH 6.0-6.8 exhibited strong acid phosphatase activity suggestive of a potential role in endocytosis in one-third of the cytoplasmic granules and also in Golgi elements. Buffy coat basophils contained about one-third as many reactive granules. Reaction product was confined to the threadlike component of the larger granules predominant in early basophils and was absent from the denser-type granules predominant in late basophils. In centrioles of basophils acid phosphatase appeared localized between triplet fibers. Reactivity with the Gomori medium was diminished at pH 5.0, absent at pH 8.0 and only slightly decreased with p-nitrophenyl phosphate as substrate. Basophils incubated in Barka-Anderson medium at pH 5.0-6.8 revealed light acid phosphatase activity in the Golgi lamellae but essentially none in cytoplasmic granules. Tris-maleate buffer of the Barka-Anderson medium replacing the sodium acetate of the Gomori medium inhibited the reactivity in the granules. Incubation in media containing NaF, or lacking substrate, eliminated the heavy precipitates in granules and Golgi elements but yielded light, nonenzymatic lead staining in Golgi and tubulovesicular structures and atypical granules present only in buffy coat basophils.

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