Experimental IgA nephropathy in bile duct ligated rats.

Polymeric IgA and polymeric IgA-containing immune complexes are transported from blood to bile through hepatocyte-bound secretory component. In order to investigate interruption of this transport and its effect on the glomerulus, Sprague-Dawley rats underwent bile duct ligation. Renal tissue obtained at the time of sacrifice was stained by immunofluorescent techniques with antibodies to IgG, IgM, and IgA, and secretory component (SC) and C3. A progressive selective increase in the staining intensity of the glomerular mesangium was observed for IgA, C3, and SC in bile duct ligated rats. These changes were paralleled by a rise in serum IgA and C3. These findings are consistent with the view that glomerular deposition of IgA, C3, and SC in bile duct ligated rats may result from impairment of normal handling of polymeric IgA and polymeric IgA-containing immune complexes.