Elemental and structural studies of the rat galactose cataract.
A series of rat galactose lenses, from 1 to 20 days on the 50% galactose diet, were frozen in the whole eye, and fractured from pole to pole in the frozen state. Lyophilized half-lenses were prepared for analysis by energy dispersive spectrometry (EDS). Following elemental analysis, some specimens were embedded and sectioned for histological studies. Elemental X-ray maps, and/or profiles, were made for K, Na, Cl, Ca, P, and S. As early as two days on the galactose diet, a crescent-shaped region ("streak") of Cl, Na, and Ca gain, and K loss develops near the equatorial surface. Between this region and the equatorial surface are the nucleated differentiating fiber cells which maintain low Cl, Na, and Ca, and high K (viable equatorial zone, VEZ). With time the "streak" expands anteriorly, centrally and posteriorly, eventually (by 20 days) including most of the lens. The VEZ, including the epithelium, however, is non-reactive to the galactose diet, which is deleterious to the fully differentiated fiber cells. Eventually, the VEZ undergoes a characteristic morphological change, apparently due in part to changes in its physical environment.
Harding
C V
CV
Kresge Eye Institute, Wayne State University, School of Medicine.
Unakar
N J
NJ
Bagchi
M
M
Chylack
L T
LT
Jampel
R S
RS
Bobrowski
W F
WF
Dang
L
L
Tsui
J Y
JY
Harding
D
D
D000818:Animals; D002386:Cataract / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D004032:Diet; D004573:Electrolytes / Q000378:metabolism*; D004577:Electron Probe Microanalysis; D005260:Female; D005690:Galactose / Q000009:adverse effects*; D007908:Lens, Crystalline / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains
D004573:Electrolytes; D005690:Galactose