Cataracts in the aging rat lens. Morphology and acid phosphatase histochemistry of incipient forms

Gorthy, Willis C.

doi:10.1016/0014-4835(78)90165-3

Cited by 32 publications

(19 citation statements)

References 22 publications

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“…The ultrastructural changes observed in this study are, in many respects, similar to those seen in galactose-induced cataracts in young rats [Unakar et al, 1978], However, membrane-bound vesicles observed in young rats [Unakar et al, 1978] and in senile cataracts [Gorthy, 1977[Gorthy, , 1978, which are thought to be lysosomes, are not present in a significant amount in the neo natal lenses. The exact mechanism by which tissue debris is removed during the restoration of lens transparency in the neonatal lens remains to be eluci dated.…”

Section: Discussionmentioning

confidence: 56%

Regression of Cataracts in the Offspring of Galactose Fed Rats

Unakar¹,

Smart²,

Reddan³

et al. 1979

Ophthalmic Res

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3 days after conception, pregnant Sprague-Dawley rats were fed a diet of galactose + ground lab chow, glucose + ground lab chow, or ground lab chow alone. After delivery, mothers were fed lab chow alone. The offspring were sacrified at 0, 5, 10, 20 and 30 days after birth. Lenses were fixed and processed for light and electron microscopy. Gross observation showed that lenses from offspring of animals fed lab chow or lab chow + glucose were transparent at all times. In contrast, lenses from the offspring of galactose-fed mothers were totally opaque at birth. At 10 and 20 days postpartum the lenses from the offspring of galactose-fed animals displayed opaque regions which were interspersed with transparent areas. Opacities were no longer noted at 30 days postnatal. Thus, at the gross level, the cataracts formed during the period of fetal development appear to be completely reversible. At the ultrastructural level, the overall orientation of the epithelium and the overlying capsule was similar in all lenses examined. However, in the experimental group the fiber membranes were disrupted, and larger inter- and intracellular spaces were noted. The fibers were swollen and contained electron-dense aggregates of variable size. The extent of the galactose-induced damage assessed at the fine structural level regressed as the age of the offspring increased. Lenses and plasma from neonates and mothers were subjected to gas-liquid chromatography for determination of hexoses and polyols. Elevated levels of hexoses and polyols were found in the lenses and plasma of the newborn rats which had been exposed to galactose suggesting that the accumulation of polyols, which triggers cataract formation in older animals, also initiates cataract formation in the newborn.

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Section: Discussionmentioning

confidence: 56%

Regression of Cataracts in the Offspring of Galactose Fed Rats

Unakar¹,

Smart²,

Reddan³

et al. 1979

Ophthalmic Res

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“…So, for their development a gradual growth and maturation as part of the lens fibre membrane seem at least possible. Their function remains to be elucidated, but considering their association with lysosomal markers [24], these multilamellar bodies may be connected with the removal of damaged membranes and/or cytoplasm. However, a continuity of the membranes of the small vesicles with the lens fibre membranes was never observed, neither in sectioned material nor in the replicas, and these abnormalities were never observed outside of a narrow zone in the equator of the lens.…”

Section: Discussionmentioning

confidence: 99%

Cholesterol Content of Focal Opacities and Multilamellar Bodies in the Human Lens: Filipin Cytochemistry and Freeze Fracture

VanMarle

Vrensen

2000

Ophthalmic Res

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Adult human lenses with focal opacities were processed for normal as well as freeze fracture electron microscopy. Cholesterol was demonstrated using filipin cytochemistry. Filipin cytochemistry in combination with freeze fracture revealed that the amount of cholesterol in the normal fibre membranes was fully comparable with the amount of cholesterol in the deviating membranes of the focal opacities and the multilamellar bodies. As regards the cholesterol/phospholipid ratio, the deviating membranes have the same state of maturation as the surrounding normal lens fibre membranes, which implies that their synthesis is as highly coordinated as the synthesis of the normal lens fibre membranes.

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“…Several investigators have suggested some pathologic role of lysosomal enzymes in aging and in cataracts (1,4,11,12,(15)(16)(17). Unaker et al (16,17) have reported that the ACPase activity increased during the induction of galactose cataracts and the Part of this study was presented at the thirtieth annual meeting of the Japan Society of Histochemistry and Cytochemistry held in Kyoto on October 23-25, 1989 (Tanaka, T., Sakai, M., Ihara, N. and Ogawa, K.: Localization of Acid Phosphatase Activity in the Lenses of ICR Rats).…”

mentioning

confidence: 99%

“…reaction product was observed not only on the lateral and apical surfaces of the epithelial cells but also extracellularly on the anterior superficial cortical fiber membranes. Gorthy also reported that the swelling and degeneration of the cortical fibers occurring in the initial stages of murine senile cataracts might be caused by intercellularly located hydrolases, secreted by the Golgi/lysosomal system within the epithelium and cortex and, possibly, by the cortical smooth endoplasmic reticulum (4). On the other hand, there is a conflicting opinion that threre is no evidence for the existence of an acid protease in the cataractous human lens (13).…”

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confidence: 99%