Vitamin A homeostasis by hepatic stellate cells

点击翻译按钮获取中文摘要

Vitamin A is a fat-soluble vitamin needed for many physiological functions including vision, reproduction, embryonic development, and epithelial maintenance. Vitamin A levels in the bloodstream are kept within a range around 2 μM in humans. The Japanese lamprey, Lethenteron japonicum, stores a high concentration of vitamin A. We have cloned a lamprey cDNA for cellular retinolbinding protein (CRBP). The cloned CRBP did not bind to retinal. The CRBP mRNA showed the highest expression within the intestine. Adult lamprey may not require CRBP binding to retinal in order to effectively absorb vitamin A from fish blood. As a result, lamprey CRBP may have lost the affinity for retinal, while retaining the affinity for retinol.