Gerlach T H, Zile M H
Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224.
FASEB J. 1990 May;4(8):2511-7. doi: 10.1096/fasebj.4.8.2335274.
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.
通过结扎肾动脉制备无滤过功能肾脏的大鼠，对其血清维生素A稳态进行了研究。在急性肾衰竭的1 - 2小时内，血清视黄醇水平升高了11 - 73%，并至少维持4小时。血清视黄醇增加量的90%以上与视黄醇结合蛋白 - 甲状腺素转运蛋白（RBP - TTR）复合物中的视黄醇有关。短期急性肾衰竭未改变酰基辅酶A：视黄醇酰基转移酶和视黄醇棕榈酸酯水解酶的活性。术前3小时口服3H标记的视黄醇，与假手术大鼠相比，急性肾衰竭大鼠血清视黄醇 - RBP - TTR复合物中的氚含量多出350%；这种增加代表了RBP - TTR中视黄醇的一部分，由新吸收的3H标记视黄醇中的肝脏视黄醇贡献。视黄醇 - RBP - TTR复合物中的总视黄醇仅增加了60%。我们得出结论，短期急性肾衰竭会导致血清视黄醇 - RBP - TTR快速上调；增加的程度取决于肝脏维生素A储备的量，特别是视黄醇池。我们推测，肾脏调节从新获得的视黄醇池中肝脏释放视黄醇 - RBP的过程。
