Dose-dependent alterations in nerve polyols and (Na+,K+)-ATPase activity in galactose intoxication.
Nerve polyol content and (Na+,K+)-adenosine triphosphatase (ATPase) activity of nerve homogenates were studied in a colony of rats fed diets containing either 0%, 10%, 20%, or 40% galactose for 4 months. Nerve water and dulcitol content exhibited dose-dependent increases, whereas nerve myo-inositol content declined with increasing dietary galactose. Homogenate (Na+,K+)-ATPase activity increased with increasing galactose consumption of up to 20% dietary intake and thereafter remained consistently elevated at twice the activity of 0% galactose-fed values. Nerves of rats fed 40% galactose were also examined at the light microscope level and showed evidence of both edema and myelin splitting. These data demonstrate that increased nerve water content, dulcitol accumulation, and myo-inositol depletion parallel the previously reported dose-related increase of endoneurial fluid sodium and chloride in nerves of galactose-fed rats and suggest that elevated nerve homogenate (Na+,K+)-ATPase activity may be related to one or more of these consequences of exaggerated polyol pathway flux.
Mizisin
A P
AP
Department of Pathology, School of Medicine, University of California, San Diego, La Jolla 92093.
Calcutt
N A
NA
D000818:Animals; D001834:Body Water / Q000378:metabolism; D050260:Carbohydrate Metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005690:Galactose / Q000009:adverse effects*; D009417:Nerve Tissue / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012584:Sciatic Nerve / Q000378:metabolism / Q000473:pathology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D011108:Polymers; C024617:polyol; D000254:Sodium-Potassium-Exchanging ATPase; D005690:Galactose