Antigenic similarities among rodent urinary tract glycoproteins

Urinary glycoconjugates (glycosaminoglycans, glycoproteins, mucopolysaccharides) have been postulated as the natural defense mechanisms which prevent urinary tract infections. As a direct approach to establish the validity of this hypothesis, we have prepared a glycoprotein fraction (GP1) from rabbit bladder mucosal tissue and shown that it may be involved in the prevention of bacterial adherence. Immunohistochemical studies using fluorescence have demonstrated that murine antibodies raised to rabbit GP1 can be used as a semiquantitative index of glycoprotein production. The present investigation addresses the question of the species restriction of the glycoprotein--whether it is confined to the rabbit or whether a similar or identical substance occurs in other species. Using an immunoperoxidase staining technique, we have examined the genitourinary tracts of Sprague Dawley rats, Golden hamsters, and Hartley guinea pigs. Mouse anti-rabbit GP1 was used as the primary antibody with an avidin-biotin complexing system. All three species reacted well with the murine antiserum but were negative with normal sera. Semiquantitative estimates of the relative amounts of this material in different areas of the genitourinary tract showed that the distal renal tubules, renal pelvic mucosa, ureters and bladders were rich in this glycoprotein while urethra and vagina were not.