Effects of vitamin A status on cellular retinoic acid-binding protein in rat skin and testes.
Cellular retinoic acid-binding protein levels were determined in the skin and testes of normal and retinol-deficient rats. All-trans [3H]retinoic acid (1.1 TBq/mmol) was used to titrate the specific binding sites in tissue cytosol preparations. Scatchard plot analyses were used to determine the concentration of cellular retinoic acid-binding protein and its binding affinity (Kd) for all-trans-retinoic acid. In normal rat skin the concentration of cellular retinoic acid-binding protein was 3317 +/- 924 (SD) fmol/mg protein and the Kd was 1.98 +/- 1.0 x 10(-9) mol/l. In retinol-deficient rat skin the concentration of cellular retinoic acid-binding protein was 2584 +/- 1205 fmol/mg protein and the Kd was 3.30 +/- 3.4 x 10(-9) mol/l. In the normal rat testes the concentration of cellular retinoic acid-binding protein was 2965 +/- 1187 fmol/mg protein and the Kd was 2.30 +/- 2.1 x 10(-9) mol/l. In retinol-deficient rat testes the concentration of cellular retinoic acid-binding protein was 2439 +/- 383 fmol/mg protein and the Kd was 0.3 +/- 0.2 x 10(-9) mol/l. These findings indicate that there are no significant differences in the levels of cellular retinoic acid-binding protein between normal and deficient rat skin and testes (p greater than 0.1, by Wilcoxon rank sum test). We therefore conclude that the level of cellular retinoic acid-binding protein in skin and testes may not be controlled by the availability of vitamin A.
Madani
K A
KA
Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana.
Bazzano
G S
GS
Chou
A C
AC
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D018168:Receptors, Retinoic Acid; D012867:Skin / Q000737:chemistry*; D013737:Testis / Q000737:chemistry*; D014801:Vitamin A / Q000032:analysis*; D014802:Vitamin A Deficiency / Q000378:metabolism
D002352:Carrier Proteins; D018168:Receptors, Retinoic Acid; D014801:Vitamin A