ELECTRON PROBE ANALYSIS OF THE CALCIUM DISTRIBUTION IN CELLS OF THE EMBRYONIC CHICK CHORIOALLANTOIC MEMBRANE II. DEMONSTRATION OF INTRACELLULAR LOCATION DURING ACTIVE TRANSCELLULAR TRANSPORT

Electron probe analysis of the embryonic chick chorioallantoic membrane reveals that calcium is located at discrete sites in the ectodermal cell layer of the membrane. The calcium loci are found at characteristic sites within distinctive "capillary-covering" cells. Evidence is presented that the calcium identified by electron probe analysis is that pool of calcium undergoing active transcellular transport. Mitochondria and/or endoplasmic reticulum do not appear to be responsible for the observed calcium sequestration. It is suggested that the calcium might be contained within endocytotic vesicles, and a hypothesis is advanced which could reconcile endocytotic transcellular transport by specialized cells with previously proposed models for intracellular calcium ion regulation.

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ELECTRON PROBE ANALYSIS OF THE CALCIUM DISTRIBUTION IN CELLS OF THE EMBRYONIC CHICK CHORIOALLANTOIC MEMBRANE I. A CRITICAL EVALUATION OF TECHNIQUES

Journal of Histochemistry & Cytochemistry ◽

10.1177/20.6.401 ◽

1972 ◽

Vol 20 (6) ◽

pp. 401-413 ◽

Cited By ~ 28

Author(s):

JAMES R. COLEMAN ◽

A. RAYMOND TEREPKA

Keyword(s):

Electron Probe ◽

Critical Evaluation ◽

Chorioallantoic Membrane ◽

Embryonic Chick ◽

Total Calcium ◽

Electron Probe Analysis ◽

X Ray ◽

Chick Chorioallantoic Membrane ◽

Minor Losses

The chorioallantoic membrane of the developing chick embryo is an epithelium that actively transports calcium. The methodology utilized to prepare this soft tissue for calcium localization with the electron probe x-ray microanalyzer is presented in detail. The preparative procedures are evaluated according to general histochemical principles and in relationship specifically to electron probe investigations. It is shown that the method employed in these studies preserves the normal fine structure of the tissue, prevents selective loss of calcium, permits only minor losses of total calcium and appears to maintain the distribution of calcium that existed in vivo. Examples are presented of artifacts that can be induced during tissue sectioning and mounting procedures. Problems of defining electron probe resolution in biologic specimens are discussed, and the critical importance of evaluating x-ray images in association with simultaneously generated sample current images is emphasized.

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Electron probe analysis of calcium distribution during active transport in chick chorioallantoic membrane

Experimental Cell Research ◽

10.1016/0014-4827(70)90356-3 ◽

1970 ◽

Vol 63 (1) ◽

pp. 216-220 ◽

Cited By ~ 17

Author(s):

J.R. Coleman ◽

S.M. DeWitt ◽

P. Batt ◽

A.R. Terepka

Keyword(s):

Active Transport ◽

Electron Probe ◽

Chorioallantoic Membrane ◽

Electron Probe Analysis ◽

Calcium Distribution ◽

Chick Chorioallantoic Membrane ◽

Probe Analysis

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ACTIVE TRANSCELLULAR TRANSPORT OF CALCIUM BY EMBRYONIC CHICK CHORIOALLANTOIC MEMBRANE

Cellular Mechanism for Calcium Transfer and Homeostasis ◽

10.1016/b978-0-12-518050-4.50025-2 ◽

1971 ◽

pp. 371-389 ◽

Cited By ~ 7

Author(s):

A. Raymond Terepka ◽

James R. Coleman ◽

James C. Garrison ◽

Robert F. Spataro

Keyword(s):

Chorioallantoic Membrane ◽

Embryonic Chick ◽

Transcellular Transport ◽

Chick Chorioallantoic Membrane

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Electron Probe Analysis of Muscle

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054583 ◽

1982 ◽

Vol 40 ◽

pp. 398-401

Author(s):

A. V. Somlyo ◽

H. Shuman ◽

A. P. Somlyo

Keyword(s):

Skeletal Muscle ◽

Smooth Muscle ◽

Sarcoplasmic Reticulum ◽

Resting State ◽

Binding Sites ◽

Electron Probe ◽

Frog Skeletal Muscle ◽

Electron Probe Analysis ◽

Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

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The use of a Bent Grid to Improve the take-Off Angle for Electron Probe Analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091780 ◽

1976 ◽

Vol 34 ◽

pp. 360-361

Author(s):

Delbert E. Philpott ◽

David Leaffer

Keyword(s):

Quantitative Analysis ◽

Tilt Angle ◽

Count Rate ◽

Electron Probe ◽

Open Area ◽

Electron Probe Analysis ◽

Background Ratio ◽

Probe Analysis

There are certain advantages for electron probe analysis if the sample can be tilted directly towards the detector. The count rate is higher, it optimizes the geometry since only one angle need be taken into account for quantitative analysis and the signal to background ratio is improved. The need for less tilt angle may be an advantage because the grid bars are not moved quite as close to each other, leaving a little more open area for observation. Our present detector (EDAX) and microscope (Philips 300) combination precludes moving the detector behind the microscope where it would point directly at the grid. Therefore, the angle of the specimen was changed in order to optimize the geometry between the specimen and the detector.

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Electron Probe Analysis of Vertebrate Smooth Muscle: Distribution of Ca and Ci

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091652 ◽

1976 ◽

Vol 34 ◽

pp. 334-335 ◽

Cited By ~ 1

Author(s):

Avril V. Somlyo ◽

H. Shuman ◽

A.P. Somlyo

Keyword(s):

Smooth Muscle ◽

Electron Probe ◽

Preliminary Report ◽

Cell Damage ◽

Electron Probe Analysis ◽

Perinuclear Space ◽

Probe Analysis ◽

High K ◽

Low K ◽

Initial Results

This is a preliminary report of electron probe analysis of rabbit portal-anterior mesenteric vein (PAMV) smooth muscle cryosectioned without fixation or cryoprotection. The instrumentation and method of electron probe quantitation used (1) and our initial results with cardiac (2) and skeletal (3) muscle have been presented elsewhere.In preparations depolarized with high K (K2SO4) solution, significant calcium peaks were detected over the sarcoplasmic reticulum (Fig 1 and 2) and the continuous perinuclear space. In some of the fibers there were also significant (up to 200 mM/kg dry wt) calcium peaks over the mitochondria. However, in smooth muscle that was not depolarized, high mitochondrial Ca was found in fibers that also contained elevated Na and low K (Fig 3). Therefore, the possibility that these Ca-loaded mitochondria are indicative of cell damage remains to be ruled out.

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