Protective effects of estrogen in a rat model of age-related cataracts

Robert Bigsby, Horacio Cardenas, Andrea Caperell-Grant, Clinton J. Grubbs

Research output: Contribution to journalArticle

67 Citations (Scopus)

Abstract

Women have a higher incidence of cataracts, and epidemiologic data suggest that the increased risk may be caused by a lack of estrogen in postmenopausal years. We have examined the effects of estrogen on methyinitrosourea (MNU)-induced cataractogenesis in Sprague-Dawley rats. Animals were ovariectomized, injected with MNU, and treated with estradiol or estrone by a continuous-release, subcutaneous Silastic implant, or they received an empty Silastic implant (no hormone). In the no-hormone group, rats developed opaque lenses approximately 6 months after MNU treatment. By 8 months, 74% (14/19) of the no-hormone rats had evident opacity in one or both eyes by simple gross inspection; 58% (22/38) of the eyes in this group were opaque. Estradiol or estrone treatment reduced the incidence of cataractous eyes to 12% or 25%, respectively. Lenses were examined under a dissecting microscope for light transmission. The lenses of the group treated with no hormone had light transmission of 26% ± 9.2%, whereas lenses from the estradiol-treated animals had light transmission of 72% ± 5.8%. Histological examination revealed that the anterior cortices of the opaque lenses were disrupted and showed the hallmark signs of age-related cataracts; in addition, some eyes that appeared clear by macroscopic examination showed the early histologic signs of cataractogenesis. It was demonstrated with reverse transcription-PCR that lens cells express both α and β types of estrogen receptor, suggesting that the protective effects of the hormones may be a direct, receptor-mediated phenomenon. Thus, the MNU-treated, ovariectomized rat serves as a model for age-related cataractogenesis, and observation of a clear protective effect of estrogens in this system supports the implications of epidemiologic data.

Original languageEnglish
Pages (from-to)9328-9332
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume96
Issue number16
DOIs
StatePublished - Aug 3 1999

Fingerprint

Cataract
Lenses
Estrogens
Hormones
Estradiol
Estrone
Light
Naphazoline
Incidence
Estrogen Receptors
Reverse Transcription
Sprague Dawley Rats
Observation
Polymerase Chain Reaction
Therapeutics
baysilon

ASJC Scopus subject areas

  • Genetics
  • General

Cite this

Protective effects of estrogen in a rat model of age-related cataracts. / Bigsby, Robert; Cardenas, Horacio; Caperell-Grant, Andrea; Grubbs, Clinton J.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 96, No. 16, 03.08.1999, p. 9328-9332.

Research output: Contribution to journalArticle

Bigsby, Robert ; Cardenas, Horacio ; Caperell-Grant, Andrea ; Grubbs, Clinton J. / Protective effects of estrogen in a rat model of age-related cataracts. In: Proceedings of the National Academy of Sciences of the United States of America. 1999 ; Vol. 96, No. 16. pp. 9328-9332.
@article{ad76065fe4f143bd8b5ecec17fcea63d,
title = "Protective effects of estrogen in a rat model of age-related cataracts",
abstract = "Women have a higher incidence of cataracts, and epidemiologic data suggest that the increased risk may be caused by a lack of estrogen in postmenopausal years. We have examined the effects of estrogen on methyinitrosourea (MNU)-induced cataractogenesis in Sprague-Dawley rats. Animals were ovariectomized, injected with MNU, and treated with estradiol or estrone by a continuous-release, subcutaneous Silastic implant, or they received an empty Silastic implant (no hormone). In the no-hormone group, rats developed opaque lenses approximately 6 months after MNU treatment. By 8 months, 74{\%} (14/19) of the no-hormone rats had evident opacity in one or both eyes by simple gross inspection; 58{\%} (22/38) of the eyes in this group were opaque. Estradiol or estrone treatment reduced the incidence of cataractous eyes to 12{\%} or 25{\%}, respectively. Lenses were examined under a dissecting microscope for light transmission. The lenses of the group treated with no hormone had light transmission of 26{\%} ± 9.2{\%}, whereas lenses from the estradiol-treated animals had light transmission of 72{\%} ± 5.8{\%}. Histological examination revealed that the anterior cortices of the opaque lenses were disrupted and showed the hallmark signs of age-related cataracts; in addition, some eyes that appeared clear by macroscopic examination showed the early histologic signs of cataractogenesis. It was demonstrated with reverse transcription-PCR that lens cells express both α and β types of estrogen receptor, suggesting that the protective effects of the hormones may be a direct, receptor-mediated phenomenon. Thus, the MNU-treated, ovariectomized rat serves as a model for age-related cataractogenesis, and observation of a clear protective effect of estrogens in this system supports the implications of epidemiologic data.",
author = "Robert Bigsby and Horacio Cardenas and Andrea Caperell-Grant and Grubbs, {Clinton J.}",
year = "1999",
month = "8",
day = "3",
doi = "10.1073/pnas.96.16.9328",
language = "English",
volume = "96",
pages = "9328--9332",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "16",

}

TY - JOUR

T1 - Protective effects of estrogen in a rat model of age-related cataracts

AU - Bigsby, Robert

AU - Cardenas, Horacio

AU - Caperell-Grant, Andrea

AU - Grubbs, Clinton J.

PY - 1999/8/3

Y1 - 1999/8/3

N2 - Women have a higher incidence of cataracts, and epidemiologic data suggest that the increased risk may be caused by a lack of estrogen in postmenopausal years. We have examined the effects of estrogen on methyinitrosourea (MNU)-induced cataractogenesis in Sprague-Dawley rats. Animals were ovariectomized, injected with MNU, and treated with estradiol or estrone by a continuous-release, subcutaneous Silastic implant, or they received an empty Silastic implant (no hormone). In the no-hormone group, rats developed opaque lenses approximately 6 months after MNU treatment. By 8 months, 74% (14/19) of the no-hormone rats had evident opacity in one or both eyes by simple gross inspection; 58% (22/38) of the eyes in this group were opaque. Estradiol or estrone treatment reduced the incidence of cataractous eyes to 12% or 25%, respectively. Lenses were examined under a dissecting microscope for light transmission. The lenses of the group treated with no hormone had light transmission of 26% ± 9.2%, whereas lenses from the estradiol-treated animals had light transmission of 72% ± 5.8%. Histological examination revealed that the anterior cortices of the opaque lenses were disrupted and showed the hallmark signs of age-related cataracts; in addition, some eyes that appeared clear by macroscopic examination showed the early histologic signs of cataractogenesis. It was demonstrated with reverse transcription-PCR that lens cells express both α and β types of estrogen receptor, suggesting that the protective effects of the hormones may be a direct, receptor-mediated phenomenon. Thus, the MNU-treated, ovariectomized rat serves as a model for age-related cataractogenesis, and observation of a clear protective effect of estrogens in this system supports the implications of epidemiologic data.

AB - Women have a higher incidence of cataracts, and epidemiologic data suggest that the increased risk may be caused by a lack of estrogen in postmenopausal years. We have examined the effects of estrogen on methyinitrosourea (MNU)-induced cataractogenesis in Sprague-Dawley rats. Animals were ovariectomized, injected with MNU, and treated with estradiol or estrone by a continuous-release, subcutaneous Silastic implant, or they received an empty Silastic implant (no hormone). In the no-hormone group, rats developed opaque lenses approximately 6 months after MNU treatment. By 8 months, 74% (14/19) of the no-hormone rats had evident opacity in one or both eyes by simple gross inspection; 58% (22/38) of the eyes in this group were opaque. Estradiol or estrone treatment reduced the incidence of cataractous eyes to 12% or 25%, respectively. Lenses were examined under a dissecting microscope for light transmission. The lenses of the group treated with no hormone had light transmission of 26% ± 9.2%, whereas lenses from the estradiol-treated animals had light transmission of 72% ± 5.8%. Histological examination revealed that the anterior cortices of the opaque lenses were disrupted and showed the hallmark signs of age-related cataracts; in addition, some eyes that appeared clear by macroscopic examination showed the early histologic signs of cataractogenesis. It was demonstrated with reverse transcription-PCR that lens cells express both α and β types of estrogen receptor, suggesting that the protective effects of the hormones may be a direct, receptor-mediated phenomenon. Thus, the MNU-treated, ovariectomized rat serves as a model for age-related cataractogenesis, and observation of a clear protective effect of estrogens in this system supports the implications of epidemiologic data.

UR - http://www.scopus.com/inward/record.url?scp=0033529774&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033529774&partnerID=8YFLogxK

U2 - 10.1073/pnas.96.16.9328

DO - 10.1073/pnas.96.16.9328

M3 - Article

C2 - 10430942

AN - SCOPUS:0033529774

VL - 96

SP - 9328

EP - 9332

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 16

ER -