Antibacterial activity of bladder surface mucin duplicated by exogenous glycosaminoglycan (heparin)

We have previously shown that the transitional cells lining the urinary bladder are capable of producing glycosaminoglycan (GAG). By use of a quantitative in vivo method of measuring bacterial adherence, we demonstrated that bacterial adherence to the mucosal cells is diminished in the presence of this GAG, rises when it is removed (by acid), and returns to normal when the GAG is resynthesized (in less than 24 h). We also found that this much layer could be removed (with a corresponding rise in bacterial adherence) and that addition of exogenous GAG (heparin) to the bladder prevented the expected rise in bacterial adherence. This study analyzed in depth the manner by which heparin prevents the rise in adherence seen when the mucin is removed. Pretreatment of bacteria with heparin had no effect on adherence, whereas pretreatment of the bladder with heparin inhibited adherence. To corroborate our impression that the heparin was coating the transitional cells, [3H]heparin was added to bladders after removal of mucin. Autoradiography revealed the heparin to be adherent to the surface of the transitional cells.