Localization of various phosphatase activities within the golgi apparatus and lysosomes of rat leydig cells

1986 ◽  
Vol 44 ◽  
pp. 294-295
Author(s):  
M. F. Lalli ◽  
V. Lacroix ◽  
L. Hermo ◽  
Y. Clermont ◽  
C. E. Smith
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Leydig Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Fluid Phase ◽  
Multivesicular Bodies ◽  
Golgi Stack ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Adsorptive Endocytosis

The testosterone-secreting Leydig cells contain an abundance of smooth endoplasmic reticulum, peroxisomes, mitochondria as well as a large, spheroidal, juxtanuclear Golgi apparatus composed of interconnected stacks of saccules (Figs. 1,2). Each Golgi stack appears to be composed of between 5 to 7 saccules or sacculo-tubular elements (Figs.1,2). These cells also possess pale and dense multivesicular bodies and dense membrane-bound bodies identified assecondary lysosomes, all of which have been shown to be involved in fluid phase and adsorptive endocytosis as well as in receptor mediated endocytosis. The purpose of the present study was to characterize the reactivity of Golgi saccules, multivesicular bodies and lysosomes of Leydig cells for different phosphatases.

scholarly journals Endosomes and Golgi vesicles in adsorptive and fluid phase endocytosis.

1984 ◽  
Vol 99 (4) ◽  
pp. 1379-1390 ◽  
Author(s):  
N K Gonatas ◽  
A Stieber ◽  
W F Hickey ◽  
S H Herbert ◽  
J O Gonatas
Keyword(s):  
Golgi Apparatus ◽  
Room Temperature ◽  
Fluid Phase ◽  
Intracellular Traffic ◽  
Pheochromocytoma Cells ◽  
Quantitative Studies ◽  
Fluid Phase Endocytosis ◽  
Morphometric Methods ◽  
Membrane Bound ◽  
Adsorptive Endocytosis

We studied with morphometric methods the endocytosis by pheochromocytoma cells of a conjugate of wheat germ agglutinin with ferritin (WGA-Ft) and of horseradish peroxidase (HRP). Quantitative studies indicated that WGA-Ft was cleared slowly from cell surfaces and that it was not recycled to the surface. Cells labeled with WGA-Ft for 15 min at room temperature were washed and incubated in medium containing HRP for 15 or 30 min at 37 degrees C. The greatest proportion of labeled vesicles and tubules contained only WGA-Ft (83.4% at 15 min and 85.3% at 30 min). A very small fraction of labeled vesicles and tubules contained only HRP (0.2% at 15 min and 0.9% at 30 min). Vesicles and tubules at the Golgi apparatus were labeled almost exclusively with WGA-Ft (97% at 15 min and 30 min); the rest had both labels. Most labeled lysosomes contained both labels (80.1% at 15 min and 80.8% at 30 min). Of the remainder more contained WGA-Ft alone (20% at 15 min and 10.9% at 30 min), then HRP alone (none at 15 min and 8.2% at 30 min). In contrast to the various and varying patterns of labeling with WGA-Ft and HRP of the other organelles studied, the vast majority of endosomes contained both markers (94.1% at 15 min and 100% at 30 min); the rest contained WGA-Ft only. These results demonstrate that endosomes are recipients of both fluid phase and adsorptive endocytosis markers; these findings are consistent with the hypothesis that endosomes mediate the sorting out and subsequent intracellular traffic of membrane bound and fluid phase markers. Cisterns of the Golgi apparatus did not contain WGA-Ft; in sharp contrast, when WGA-HRP was used, the cisterns of the Golgi apparatus consistently contained HRP.

scholarly journals GOLGI APPARATUS, GERL, AND LYSOSOMES OF NEURONS IN RAT DORSAL ROOT GANGLIA, STUDIED BY THICK SECTION AND THIN SECTION CYTOCHEMISTRY

1971 ◽  
Vol 50 (3) ◽  
pp. 859-886 ◽  
Author(s):  
Phyllis M. Novikoff ◽  
Alex B. Novikoff ◽  
Nelson Quintana ◽  
Jean-Jacques Hauw
Keyword(s):  
Endoplasmic Reticulum ◽  
Acid Phosphatase ◽  
Golgi Apparatus ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Smooth Endoplasmic Reticulum ◽  
Thin Sections ◽  
Golgi Stack ◽  
Golgi Element ◽  
Thiamine Pyrophosphatase

New insights into the ultrastructure and phosphatase localizations of Golgi apparatus and GERL, and into the probable origin of lysosomes in the neurons of fetal dorsal root ganglia and the small neurons of adult ganglia have come from studying thick (0.5–1.0 µ) as well as thin (up to 500 A) sections by conventional electron microscopy. Tilting the thick specimens, by a goniometer stage, has helped to increase our understanding of the three-dimensional aspects of the Golgi apparatus and GERL. One Golgi element, situated at the inner aspect of the Golgi stack, displays thiamine pyrophosphatase and nucleoside diphosphatase activities. This element exhibits regular geometric arrays (hexagons) of interconnected tubules without evidence of a flattened portion (saccule or cisterna). In contrast, GERL shows acid phosphatase activity and possesses small cisternal portions and anastomosing tubules. Lysosomes appear to bud from GERL. Osmium deposits, following prolonged osmication, are found in the outer Golgi element. Serial 0.5-µ and thin sections of thiamine pyrophosphatase-incubated material demonstrate that, in the neurons studied, the Golgi apparatus is a continuous network coursing through the cytoplasm. Serial thick sections of acid phosphatase-incubated tissue suggest that GERL is also a continuous structure throughout the cytoplasm. Tubules of smooth endoplasmic reticulum, possibly part of GERL, extend into the polygonal compartments of the inner Golgi element. The possible physiological significance of a polygonal arrangement of a phosphatase-rich Golgi element in proximity to smooth ER is considered. A tentative diagram of the Golgi stack and associated endoplasmic reticulum in these neurons has been drawn.

scholarly journals FINE STRUCTURE OBSERVATIONS OF THE UPTAKE OF INTRAVENOUSLY INJECTED PEROXIDASE BY THE RAT CHOROID PLEXUS

1967 ◽  
Vol 15 (3) ◽  
pp. 160-165 ◽  
Author(s):  
NORWIN H. BECKER ◽  
ALEX B. NOVIKOFF ◽  
H. M. ZIMMERMAN
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Cerebrospinal Fluid ◽  
Choroid Plexus ◽  
Smooth Endoplasmic Reticulum ◽  
Multivesicular Bodies ◽  
Adult Rats ◽  
Dense Bodies ◽  
Pinocytotic Vesicles ◽  
Membrane Bound

The uptake by the choroid plexus of adult rats of intravenously injected horseradish peroxidase has been investigated by electron microscopy. Within 4 min, the injected protein passes the capillary and is rapidly distributed through extracellular space and choroidal cells. Peroxidase enters the choroidal cells within coated vesicles which act as pinocytotic vesicles. At 15 min, peroxidase activity is present in numerous membrane-bound vesicles, multivesicular bodies, dense bodies and what appear to be segments of smooth endoplasmic reticulum. None of the peroxidase-containing organelles is seen to empty to the ventricular surface. Egress of the extracellular peroxidase into the cerebrospinal fluid is apparently blocked by apical zonulae occludentes between the choroidal cells.

Endocytosis and the lysosomal apparatus of rat Leydig cells

1984 ◽  
Vol 42 ◽  
pp. 708-709
Author(s):  
M.F. Lalli ◽  
L. Hermo ◽  
Y. Clermont
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Cell Surface ◽  
Leydig Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Extracellular Fluid ◽  
Multivesicular Bodies ◽  
Rat Testis ◽  
Endocytic Activity

The Leydig cells of the rat testis which are involved in testosterone production contain an abundance of smooth endoplasmic reticulum and mitochondria (Figs. 2,6). These cells also possess many peroxisomes, lysosomes and multivesicular bodies (MVB's). On the cell surface, the plasma membrane contains numerous short microvilli, small invaginations and large plasmalemmal folds which appear to engulf extracellular fluid. There are also many large dilated vacuoles adjacent to the cell surface. The purpose of the present study is to determine if these cells show endocytic activity and to differentiate by various cytochemical means lysosomal elements from peroxisomes.To identify lysosomes, tissue chopper sections of 2% glutaraldehyde-fixed testes (containing 2.5% dextran) were incubated in media containing thiamine monophosphate as a substrate (Lalli, 1983) to demonstrate the presence of acid phosphatase or in media containing P-nitrocatechol sulfate for the demonstration of arylsulfatase (Hopsu-Havu et al., 1967).

Smooth endoplasmic reticulum in perfusion and immersion-fixed Leydig cells

1990 ◽  
Vol 48 (3) ◽  
pp. 82-83
Author(s):  
R.T.F. Bernard ◽  
R.H.M. Cross
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Steroid Hormones ◽  
Transmission Electron Microscope ◽  
Leydig Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Random Mixture ◽  
Transmission Electron

Smooth endoplasmic reticulum (SER) is involved in the biosynthesis of steroid hormones, and changes in the organisation and abundance of this organelle are regularly used as indicators of changes in the level of steroidogenesis. SER is typically arranged as a meshwork of anastomosing tubules which, with the transmission electron microscope, appear as a random mixture of cross, oblique and longitudinal sections. Less commonly the SER appears as swollen vesicles and it is generally suggested that this is an artefact caused during immersion fixation or during immersion of poorly-perfused tissue.During a previous study of the Leydig cells of a seasonally reproducing bat, in which tissue was fixed by immersion, we noted that tubular SER and vesicular SER often occured in adjacent cells and sometimes in the same cell, and that the abundance of the two types of SER changed seasonally. We came to doubt the widelyheld dogma that vesicular SER was an artefact of immersion fixation and set out to test the hypothesis that the method of fixation does not modify the ultrastructure of the SER.

The Occurrence of Phenylalanine Ammonia-Lyase and Cinnamic Acid p-Hydroxylase on the Endoplasmic Reticulum of Cell Suspension Cultures of Glycine max

1978 ◽  
Vol 33 (1-2) ◽  
pp. 65-69 ◽  
Author(s):  
C. Postius ◽  
H. Kindi
Keyword(s):  
Endoplasmic Reticulum ◽  
Glycine Max ◽  
Golgi Apparatus ◽  
Cinnamic Acid ◽  
Time Course ◽  
Phenylalanine Ammonia Lyase ◽  
Plasma Membranes ◽  
Microsomal Fraction ◽  
Activity Increase ◽  
Membrane Bound

Abstract 1. The time course of activity of soluble and microsomal phenylalanine ammonia-lyase (PAL) was studied in dark grown cell cultures of soybean (Glycine max). A distinct activity increase of PAL in the soluble and microsomal fraction occurred prior to the stationary phase of the cell culture. Cinnamic acid p-hydroxylase and NADH : cytochrome c reductase, too, exhibited maximal activity in the log phase, 5 days after the transfer of soybean cells to fresh culture medium.2. Upon subfractionation of the once washed microsomal fraction by sedimentation velocity centrifugation on a sucrose gradient, membranes of the endoplasmic reticulum could be separated from fractions containing mainly membranes from the Golgi apparatus or plasma membranes, respectively. PAL and cinnamic acid p-hydroxylase were found in fractions of endoplasmic reticulum whereas no activity of either enzymes could be detected in fractions containing Golgi apparatus or plasma membranes.3. Repeated washing of microsomal fractions led to a residual membrane-bound PAL representing about 1% of the total PAL activity of the cells. This residual membrane-bound activity could be solubilized almost completely by Triton X-100 or digitonin at concentrations of 0.5 - 5%.

Studies on the site of addition of sialic acid and glucosamine to rat α1-acid glycoprotein

1977 ◽  
Vol 55 (4) ◽  
pp. 408-414 ◽  
Author(s):  
J. C. Jamieson
Keyword(s):  
Endoplasmic Reticulum ◽  
Sialic Acid ◽  
Rat Liver ◽  
Golgi Complex ◽  
Smooth Endoplasmic Reticulum ◽  
Main Site ◽  
Acid Glycoprotein ◽  
Membrane Bound ◽  
Polypeptide Chains

Ultrasonic extracts of rough and smooth endoplasmic reticulum fractions and Golgi fractions from rat liver were examined by immunoelectrophoresis using antiserum to α1-acid glycoprotein. Rough endoplasmic reticulum fractions contained only sialic acid free α1-acid glycoprotein, whereas smooth endoplasmic reticulum and Golgi fractions also contained sialic acid containing α1-acid glycoprotein. Determination of the sialic acid contents of immune precipitates isolated from the extracts suggested that the Golgi complex was the main site of addition of sialic acid to α1-acid glycoprotein. Immunological studies on puromycin extracts of polyribosomes showed that polypeptide chains of α1-acid glycoprotein and albumin were assembled mainly on membrane-bound polyribosomes. Evidence is presented from incorporation studies with labelled leucine and glucosamine that initial glycosylation of α1-acid glycoprotein occurs mainly or entirely after release of nascent polypeptide from the ribosomal site.

scholarly journals Proteolytic activation and solubilization of endoplasmic-reticulum cyclic AMP phosphodiesterase activity

1983 ◽  
Vol 213 (1) ◽  
pp. 99-105 ◽  
Author(s):  
S R Wilson ◽  
M D Houslay
Keyword(s):  
Endoplasmic Reticulum ◽  
Proteinase Inhibitors ◽  
Smooth Endoplasmic Reticulum ◽  
Limited Proteolysis ◽  
Proteolytic Activation ◽  
Freeze Thaw ◽  
Membrane Bound ◽  
Time Courses ◽  
Triton X ◽  
Thiol Proteinase

Dithiothreitol led to the activation and solubilization of the cyclic nucleotide phosphodiesterase activities associated with the smooth and various rough subfractions of rat liver endoplasmic reticulum. The activity in each of the subfractions exhibited somewhat different time courses, and sensitivities to dithiothreitol concentration, in respect of their solubilization and activation. Both activation and solubilization by dithiothreitol could be blocked by either thiol proteinase inhibitors or excess bovine serum albumin. Freeze-thaw solubilization was not blocked by the thiol proteinase inhibitor antipain and did not lead to the activation of the enzyme. After dithiothreitol-induced solubilization, all of the enzymes exhibited non-linear Lineweaver-Burk plots indicative of apparent negative co-operativity. In contrast, after freeze-thaw solubilization the enzyme in the smooth-endoplasmic-reticulum-plus-Golgi fraction still obeys Michaelis kinetics, as does the membrane-bound enzyme. It is possible to mimic the action of dithiothreitol in solubilizing and activating the enzyme by limited proteolysis with trypsin. Triton X-100 is highly efficient at solubilizing these enzymes, yet has little effect on their activities. Charged detergents exhibit highly selective effects on the enzymes as regards their solubilization and activity expressed.

scholarly journals Properties of membrane-bound bilirubin UDP-glucuronyltransferase in rough and smooth endoplasmic reticulum and in the nuclear envelope from rat liver

1989 ◽  
Vol 259 (3) ◽  
pp. 659-663 ◽  
Author(s):  
F Vanstapel ◽  
L Hammaker ◽  
K Pua ◽  
N Blanckaert
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Rat Liver ◽  
Smooth Endoplasmic Reticulum ◽  
Membrane System ◽  
Permeability Barrier ◽  
Membrane Bound ◽  
Marker Studies ◽  
High Degree ◽  
Regulatory Properties

We examined regulatory properties of bilirubin UDP-glucuronyltransferase in sealed RER (rough endoplasmic reticulum)- and SER (smooth endoplasmic reticulum)-enriched microsomes (microsomal fractions), as well as in nuclear envelope from rat liver. Purity of membrane fractions was verified by electron microscopy and marker studies. Intactness of RER and SER vesicles was ascertained by a high degree of latency of the lumenal marker mannose-6-phosphatase. No major differences in the stimulation of UDP-glucuronyltransferase by detergent or by the presumed physiological activator, UDPGlcNAc, were observed between total microsomes and RER- or SER-enriched microsomes. Isolated nuclear envelopes were present as a partially disrupted membrane system, with approx. 50% loss of mannose-6-phosphatase latency. The nuclear transferase had lost its latency to a similar extent, and the enzyme failed to respond to UDPGlcNAc. Our results underscore the necessity to include data on the integrity of the membrane permeability barrier when reporting regulatory properties of UDP-glucuronyltransferase in different membrane preparations.

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