Quantitation of cellular retinol-binding protein in human organs.

Levels of cellular retinol-binding protein (CRBP) have been determined for a number of human tissues by a sensitive radioimmunoassay. The protein was detectable in at least one sample of every tissue examined. Samples with the highest levels were obtained from adrenal, liver, ovary, pituitary, and testis. The relative abundance of CRBP was significantly different from the relative abundance for rat organs. The wide distribution of CRBP in human organs stresses the importance of this protein in the metabolism of vitamin A throughout the body.