Zonal variation in the distribution of an α1-acid glycoprotein glycoform receptor in human adrenal cortex

Using a histochemical technique with three different alpha(1)-acid glycoprotein glycoforms, one glycoform specific receptor has been identified in human adrenal cortex. The receptor is associated to alpha(1)-acid glycoprotein glycoform B and alpha(1)-acid glycoprotein glycoform C. The glycoform specific receptor was located in the cytoplasm of glomerulosa and outer fasciculata cells. The intensity of the reaction product decreased in the fasciculata, and no staining was seen in inner fasciculata and reticularis. Inhibition with the simple sugars, mannose and GlcNAc confirmed a lectin-like reaction. The binding activity was dependent on the presence of calcium ions and not on thiol reagents. Thus the lectin-like receptor may belong to the C-type lectin family. Using an antibody to alpha(1)-acid glycoprotein the presence of alpha(1)-acid glycoprotein was observed in the same location as the glycoform specific receptor. The binding of alpha(1)-acid glycoprotein glycoform B and alpha(1)-acid glycoprotein glycoform C to the glycoform specific receptor is inhibited by the steroid hormones cortisone, aldosterone, estradiol and progesterone but not by testosterone. The pronounced changes in the distribution of AGP and its glycoform receptors during cell differentiation in the adrenal cortex suggest that AGP and its complementary lectins belong to the group of lectins which control differentiation and spatial position.