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 language | English (US) |
|---|---|
| Pages (from-to) | 586-592 |
| Number of pages | 7 |
| Journal | Investigative Ophthalmology and Visual Science |
| Volume | 38 |
| Issue number | 3 |
| State | Published - 1997 |
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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 journal › Article
}
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
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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 -