Alterations in the light transmission through single lens fibers during calcium-mediated disintegrative globulization

Aruni Bhatnagar, Prajay Dhir, Le Fei Wang, Naseem Ansari, WooKuen Lo, Satish Srivastava

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Purpose. The purpose of this study was to examine changes in the light transmission through single cortical fibers isolated from the rat lens during the process of disintegrative globulization. Methods. Single cortical fibers were isolated from adult rat lens by treatment with trypsin in a solution containing 10 mM HEPES, 10 mM EDTA, and 280 mM sucrose (pH 7.4, 300 to 310 mOsm) HEPES-EDTA-sucrose (HES) solution. The isolated fibers were illuminated by a white light source, and the light transmission through the fibers was collected by a charge-coupled device camera and quantified by digital image analysis. In some experiments, thin sections of fixed lens cells were examined using transmission electron microscopy. Results. Enzymatic dissociation of the lens yielded elongated fibers, which, in the presence of Ringer's solution (containing 2 mM Ca2+), underwent disintegrative globulization. Measurements of light transmission through elongated fibers suspended in HES solution showed maximal transmission at the center of the fiber. Exposure of the cortical fibers to Ringer's solution led to biphasic changes in the intensity of the transmitted light. Within 5 to 10 minutes of exposure to Ringer's solution, a general decrease in the light transmission across the long axis of the fiber was observed. Extended superfusion led to a local, apparent increase in light transmission corresponding to the formation of membrane blebs and globules. Images of disintegrated globules focused above their equator showed bright halos with clark central zones. In electron micrographs, the single fibers showed uniform electron density. No significant inhomogeneities or precipitation of intracellular crystallins was observed in globules generated from fiber cells exposed to Ringer's solution; in addition, no high molecular weight protein aggregates were found in the globules. Conclusions. Exposure to calcium alters the light-transmitting properties of isolated cortical fibers. The initial decrease in the average light transmittance of the fiber appears to be secondary to cell swelling and may relate to protein-based opacification. An apparent increase in light transmission through calcium-generated globules is likely because of the Becke line generated by a mismatch between the refractive index of the medium and the globule cytoplasm and accentuated by the transition from rod-shaped to spheroidal morphology.

Original languageEnglish (US)
Pages (from-to)586-592
Number of pages7
JournalInvestigative Ophthalmology and Visual Science
Volume38
Issue number3
StatePublished - 1997

Fingerprint

Lenses
Calcium
Light
HEPES
Edetic Acid
Sucrose
Electrons
Refractometry
Crystallins
Blister
Transmission Electron Microscopy
Trypsin
Cytoplasm
Molecular Weight
Equipment and Supplies
Membranes
Ringer's solution

Keywords

  • calcium
  • globulization
  • lens fiber cells
  • light transmission
  • transmission electron microscopy

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Alterations in the light transmission through single lens fibers during calcium-mediated disintegrative globulization. / Bhatnagar, Aruni; Dhir, Prajay; Wang, Le Fei; Ansari, Naseem; Lo, WooKuen; Srivastava, Satish.

In: Investigative Ophthalmology and Visual Science, Vol. 38, No. 3, 1997, p. 586-592.

Research output: Contribution to journalArticle

Bhatnagar, Aruni ; Dhir, Prajay ; Wang, Le Fei ; Ansari, Naseem ; Lo, WooKuen ; Srivastava, Satish. / Alterations in the light transmission through single lens fibers during calcium-mediated disintegrative globulization. In: Investigative Ophthalmology and Visual Science. 1997 ; Vol. 38, No. 3. pp. 586-592.
@article{32b583e412ae447dbe77141585a421c4,
title = "Alterations in the light transmission through single lens fibers during calcium-mediated disintegrative globulization",
abstract = "Purpose. The purpose of this study was to examine changes in the light transmission through single cortical fibers isolated from the rat lens during the process of disintegrative globulization. Methods. Single cortical fibers were isolated from adult rat lens by treatment with trypsin in a solution containing 10 mM HEPES, 10 mM EDTA, and 280 mM sucrose (pH 7.4, 300 to 310 mOsm) HEPES-EDTA-sucrose (HES) solution. The isolated fibers were illuminated by a white light source, and the light transmission through the fibers was collected by a charge-coupled device camera and quantified by digital image analysis. In some experiments, thin sections of fixed lens cells were examined using transmission electron microscopy. Results. Enzymatic dissociation of the lens yielded elongated fibers, which, in the presence of Ringer's solution (containing 2 mM Ca2+), underwent disintegrative globulization. Measurements of light transmission through elongated fibers suspended in HES solution showed maximal transmission at the center of the fiber. Exposure of the cortical fibers to Ringer's solution led to biphasic changes in the intensity of the transmitted light. Within 5 to 10 minutes of exposure to Ringer's solution, a general decrease in the light transmission across the long axis of the fiber was observed. Extended superfusion led to a local, apparent increase in light transmission corresponding to the formation of membrane blebs and globules. Images of disintegrated globules focused above their equator showed bright halos with clark central zones. In electron micrographs, the single fibers showed uniform electron density. No significant inhomogeneities or precipitation of intracellular crystallins was observed in globules generated from fiber cells exposed to Ringer's solution; in addition, no high molecular weight protein aggregates were found in the globules. Conclusions. Exposure to calcium alters the light-transmitting properties of isolated cortical fibers. The initial decrease in the average light transmittance of the fiber appears to be secondary to cell swelling and may relate to protein-based opacification. An apparent increase in light transmission through calcium-generated globules is likely because of the Becke line generated by a mismatch between the refractive index of the medium and the globule cytoplasm and accentuated by the transition from rod-shaped to spheroidal morphology.",
keywords = "calcium, globulization, lens fiber cells, light transmission, transmission electron microscopy",
author = "Aruni Bhatnagar and Prajay Dhir and Wang, {Le Fei} and Naseem Ansari and WooKuen Lo and Satish Srivastava",
year = "1997",
language = "English (US)",
volume = "38",
pages = "586--592",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "3",

}

TY - JOUR

T1 - Alterations in the light transmission through single lens fibers during calcium-mediated disintegrative globulization

AU - Bhatnagar, Aruni

AU - Dhir, Prajay

AU - Wang, Le Fei

AU - Ansari, Naseem

AU - Lo, WooKuen

AU - Srivastava, Satish

PY - 1997

Y1 - 1997

N2 - Purpose. The purpose of this study was to examine changes in the light transmission through single cortical fibers isolated from the rat lens during the process of disintegrative globulization. Methods. Single cortical fibers were isolated from adult rat lens by treatment with trypsin in a solution containing 10 mM HEPES, 10 mM EDTA, and 280 mM sucrose (pH 7.4, 300 to 310 mOsm) HEPES-EDTA-sucrose (HES) solution. The isolated fibers were illuminated by a white light source, and the light transmission through the fibers was collected by a charge-coupled device camera and quantified by digital image analysis. In some experiments, thin sections of fixed lens cells were examined using transmission electron microscopy. Results. Enzymatic dissociation of the lens yielded elongated fibers, which, in the presence of Ringer's solution (containing 2 mM Ca2+), underwent disintegrative globulization. Measurements of light transmission through elongated fibers suspended in HES solution showed maximal transmission at the center of the fiber. Exposure of the cortical fibers to Ringer's solution led to biphasic changes in the intensity of the transmitted light. Within 5 to 10 minutes of exposure to Ringer's solution, a general decrease in the light transmission across the long axis of the fiber was observed. Extended superfusion led to a local, apparent increase in light transmission corresponding to the formation of membrane blebs and globules. Images of disintegrated globules focused above their equator showed bright halos with clark central zones. In electron micrographs, the single fibers showed uniform electron density. No significant inhomogeneities or precipitation of intracellular crystallins was observed in globules generated from fiber cells exposed to Ringer's solution; in addition, no high molecular weight protein aggregates were found in the globules. Conclusions. Exposure to calcium alters the light-transmitting properties of isolated cortical fibers. The initial decrease in the average light transmittance of the fiber appears to be secondary to cell swelling and may relate to protein-based opacification. An apparent increase in light transmission through calcium-generated globules is likely because of the Becke line generated by a mismatch between the refractive index of the medium and the globule cytoplasm and accentuated by the transition from rod-shaped to spheroidal morphology.

AB - Purpose. The purpose of this study was to examine changes in the light transmission through single cortical fibers isolated from the rat lens during the process of disintegrative globulization. Methods. Single cortical fibers were isolated from adult rat lens by treatment with trypsin in a solution containing 10 mM HEPES, 10 mM EDTA, and 280 mM sucrose (pH 7.4, 300 to 310 mOsm) HEPES-EDTA-sucrose (HES) solution. The isolated fibers were illuminated by a white light source, and the light transmission through the fibers was collected by a charge-coupled device camera and quantified by digital image analysis. In some experiments, thin sections of fixed lens cells were examined using transmission electron microscopy. Results. Enzymatic dissociation of the lens yielded elongated fibers, which, in the presence of Ringer's solution (containing 2 mM Ca2+), underwent disintegrative globulization. Measurements of light transmission through elongated fibers suspended in HES solution showed maximal transmission at the center of the fiber. Exposure of the cortical fibers to Ringer's solution led to biphasic changes in the intensity of the transmitted light. Within 5 to 10 minutes of exposure to Ringer's solution, a general decrease in the light transmission across the long axis of the fiber was observed. Extended superfusion led to a local, apparent increase in light transmission corresponding to the formation of membrane blebs and globules. Images of disintegrated globules focused above their equator showed bright halos with clark central zones. In electron micrographs, the single fibers showed uniform electron density. No significant inhomogeneities or precipitation of intracellular crystallins was observed in globules generated from fiber cells exposed to Ringer's solution; in addition, no high molecular weight protein aggregates were found in the globules. Conclusions. Exposure to calcium alters the light-transmitting properties of isolated cortical fibers. The initial decrease in the average light transmittance of the fiber appears to be secondary to cell swelling and may relate to protein-based opacification. An apparent increase in light transmission through calcium-generated globules is likely because of the Becke line generated by a mismatch between the refractive index of the medium and the globule cytoplasm and accentuated by the transition from rod-shaped to spheroidal morphology.

KW - calcium

KW - globulization

KW - lens fiber cells

KW - light transmission

KW - transmission electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=0030901197&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030901197&partnerID=8YFLogxK

M3 - Article

VL - 38

SP - 586

EP - 592

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 3

ER -