Effect of retinoic acid and apo-RBP on serum retinol concentration in acute renal failure.
We recently demonstrated a rapid up-regulation of serum retinol-retinol binding protein-transthyretin concentration in rats with short-term acute renal failure. We examine the effect of retinoic acid and apo-retinol binding protein (apo-RBP) on the up-regulation of serum retinol in renal failure. Injection of retinoic acid (10 micrograms) into rats with acute renal failure or sham-operated rats increased circulatory retinoic acid concentration 29-fold within 2 h but did not influence serum retinol concentration in either group. Injection of a large dose of retinoic acid (100 micrograms) decreased serum retinol concentration in rats with acute renal failure (19%) and sham-operated rats (29%). These results suggest that changes in serum retinoic acid concentration within the near-physiological range have no effect on regulation of hepatic retinol release. Injection of a large dose of retinoic acid may depress serum retinol indirectly via a retinol sparing effect in target tissues. In rats with renal failure the serum retinol concentration, elevated 44-52% above that of sham-operated controls, was also increased to 70-164% above controls by the injection of 52-63 micrograms of apo-RBP. This suggests that circulatory apo-RBP can up-regulate serum retinol. Circulatory apo-RBP may be a positive physiological feedback signal from peripheral tissues for hepatic release of 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* / Q000503:physiopathology; D000818:Animals; D001059:Apoproteins / Q000494:pharmacology*; D008099:Liver / Q000737:chemistry; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012177:Retinol-Binding Proteins / Q000494:pharmacology*; D054839:Retinol-Binding Proteins, Plasma; D014212:Tretinoin / Q000494:pharmacology*; D014801:Vitamin A / Q000097:blood* / Q000737:chemistry
D001059:Apoproteins; C101326:RBP4 protein, human; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A; D014212:Tretinoin