Upregulation of serum retinol in experimental acute renal failure.
Serum vitamin A homeostasis was studied in rats with nonfiltering kidneys prepared by ligation of renal arteries. Within 1-2 h of acute renal failure, the serum retinol level increased by 11-73% and was maintained for at least 4 h. More than 90% of the increase in serum retinol was associated with retinol in the retinol binding protein-transthyretin (RBP-TTR) complex. The activities of acyl-CoA:retinol acyltransferase and retinyl-palmitate hydrolase were not altered by short-term acute renal failure. Oral administration of 3H-labeled retinol 3 h before surgery resulted in 350% more tritium in the serum retinol-RBP-TTR complex of rats with acute renal failure as compared to sham-operated rats; this increase represented the fraction of retinol in RBP-TTR contributed by hepatic retinol from newly absorbed 3H-labeled retinol. Total retinol in the retinol-RBP-TTR complex was increased by only 60%. We conclude that short-term acute renal failure causes rapid upregulation of serum retinol-RBP-TTR; the extent of the increase depends on the magnitude of hepatic vitamin A stores, particularly the retinol pools. We hypothesize that kidney modulates the regulation of hepatic release of retinol-RBP from the pool of newly acquired retinol.
Gerlach
T H
TH
Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224.
Zile
M H
MH
D058186:Acute Kidney Injury / Q000097:blood*; D000818:Animals; D002850:Chromatography, Gel; D004195:Disease Models, Animal; D006706:Homeostasis / Q000502:physiology; D007668:Kidney / Q000502:physiology*; D008297:Male; D009392:Nephrectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012177:Retinol-Binding Proteins / Q000378:metabolism; D015854:Up-Regulation; D014801:Vitamin A / Q000097:blood*
D012177:Retinol-Binding Proteins; D014801:Vitamin A