Ultrastructural demonstration of calcium in retina, retinal pigment epithelium and choroid

Fishman, Martin L.; Oberc, Mary Ann; Hess, Helen H.; Engel, W. King

doi:10.1016/0014-4835(77)90147-6

Cited by 29 publications

(6 citation statements)

References 21 publications

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“…The localization of calcium deposits in the discs of rods is in agreement with the results of Fishman et al (1977), van Reempts et al (1982), Ungar et al (1984 and Staple et al (1987) in frogs and rats. In addition to the intradiscal deposits described by these authors, cytoplasmic deposits could be detected which might be the result of a dislocation due to a leakage of the disc membranes caused by the cytochemical treatment.…”

Section: Discussionsupporting

confidence: 81%

“…Differences in the amounts of precipitates between rods and cones are consistent with the findings of Fishman et al (1977) in frogs and might be explained by the different calcium binding properties of rod and cone macromolecules and/or by the different anatomical structures. In rods the discs are separated from the plasma membrane (Nilsson, 1965) whereas in cones, and especially in those of the fish retina, the membrane discs are continuous with the plasma membrane (for review see Cohen, 1972) so that calcium could possibly be washed out more easily during the preparation procedures.…”

Section: Freihofer Kortje and Rahmannsupporting

confidence: 77%

“…Contrary to the results of Fishman et al (1977), Ripps et al (1979), van Reempts et al (1982 and Ungar et al (1984) large amounts of calcium could not be demonstrated in mitochondria. Only fine-grained diffuse deposits were seen occasionally.…”

Section: Freihofer Kortje and Rahmanncontrasting

confidence: 41%

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Ultrastructural localization of endogenous calcium in the teleost retina

1990

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The ultrastructural localization of endogenous calcium in the retina of adult cichlid fish Oreochromis mossambicus (Teleostei) was studied using the cytochemical osmiate-bichromate method of Probst (1986). The specificity of this method for calcium localization was proven by means of EGTA treatment of ultrathin sections and electron-spectroscopic-imaging technique (ESI) with an energy-filtering transmission electron microscope (CEM 902, Zeiss). Large amounts of electron-dense calcium containing deposits were found in the outer segments of rods, in the synaptic vesicles of receptor terminals and bipolar cells, in the perinuclear space of photoreceptors and in the endoplasmic reticulum of different cell types, especially in the inner segment and fibres of photoreceptor cells. In the inner plexiform layer calcium was detected in the extracellular space with greater accumulations in the synaptic cleft. Principal differences in the localization of calcium between rods and cones and between several types of synapses and vesicles are shown. The possible role of calcium in the subcellular structures of retinal cells is discussed.

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Section: Discussionsupporting

confidence: 81%

Section: Freihofer Kortje and Rahmannsupporting

confidence: 77%

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Ultrastructural localization of endogenous calcium in the teleost retina

1990

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“…Despite the evidence that cGMP rather than calcium ions functions as the internal messenger of phototransduction, the presence of considerable calcium in the ROS has been confirmed by biochemical analyses (Hendricks et al, 1974), by.microprobe analyses (Hagins and Yoshikama, 1975;Davis, unpublished observation), and by ultrastructural histochemistry (Fishman et al, 1977;Davis, unpublished observation). The latter morphologic studies showed the calcium to be confined largely to the intradiskal spaces of the ROS vesicles.…”

Section: Discussionmentioning

confidence: 99%

Electron microscopic cytochemical localization of Ca‐ATPase in the rod outer segments of the toad Bufo marinus

et al. 1988

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Transmission electron microscopy and ultracytochemistry were employed in an attempt to localize the enzyme calcium adenosine triphosphatase (CaATPase) in the rod outer segments (ROS) of the toad retina. Utilizing a one-step incubation procedure, Ca-ATPase was identified as an electron-dense precipitate in the intradiskal spaces of the rod disks (vesicles) of the ROS. Analytical microscopy identified the reaction product as lead phosphate. The formation of the reaction product was dependent on the presence of ATP (the substrate) and calcium ions. However, calcium ions could be substituted for by magnesium ions. In addition, the reaction was vanadate sensitive. The latter is known to inhibit Ca-ATPase activity. Such data appear to indicate the presence of a Ca-Mg-ATPase in association with the rod disks. Since cyclic guanosine monophosphate (cyclic GMP), rather than calcium ions, is currently believed to be the primary intracellular messenger associated with phototransduction, the presence of an ROS Ca-ATPase may indicate other functions for this cation in the physiology and biochemistry of the visual process. Ca-ATPase might play a role in directional calcium fluxes between intracellular compartments.

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“…The use of the potassium pyroantimonate technique as a histochemical marker for ionic calcium has been successfully demonstrated in a variety of tissues [6,7,14]. However, when tissues are subjected to the aqueous media encountered in the preparative techniques for electron microscopy.…”

Section: Discussionmentioning

confidence: 98%

Ultrastructural localization of calcium in the mandibular condylar growth cartilage of the rat

Morris

Appleton

1980

Calcif Tissue Int

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The potassium pyroantimonate technique was utilized for the selective subcellular localization of calcium in the mandibular condylar cartilage of 1-day-old rats. Electron dense calcium pyroantimonate precipitates were localized principally in mitochondria and at the cell membrane of the chondrocytes. In addition, small intracellular vesicles 0.1-0.2 micrometers in diameter were observed in proximity to the cell membrane of chondrocytes of the mid-hypertrophic zone. The results suggest that these vesicles were being extruded from the cell into the extracellular matrix. Energy-dispersive analysis by X-rays confirmed that calcium is the principal cation of the electron-dense precipitates.

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Ultrastructural demonstration of calcium in retina, retinal pigment epithelium and choroid

Cited by 29 publications

References 21 publications

Ultrastructural localization of endogenous calcium in the teleost retina

Ultrastructural localization of endogenous calcium in the teleost retina

Electron microscopic cytochemical localization of Ca‐ATPase in the rod outer segments of the toad Bufo marinus

Ultrastructural localization of calcium in the mandibular condylar growth cartilage of the rat

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