Expression of the alpha 6 chain of type IV collagen in glomerular basementmembranes of healthy adult dogs

Objective-To evaluate expression of the alpha 6 chain of type IV collagen i n the glomerular basement membranes (GBM) of healthy dogs. Sample Population-Kidney specimens from 12 healthy dogs. For comparison, ki dney specimens from 8 human subjects between 25 and 83 years old also were evaluated. Procedure-Sections were immunolabeled with a monospecific antibody that cro ss-reacts with human and canine alpha 6(IV) chains and examined by means of fluorescence microscopy. Results-Immunolabeling of the alpha 6(IV) chain was not observed in GBM of 6 dogs less than or equal to 30 months old hut was observed in GBM of the r emaining 6 dogs, all of which were greater than or equal to 45 months old. Expression of the alpha 6(IV) chain was not observed in GBM of the human su bjects, regardless of the age of the subject. Conclusions and Clinical Relevance-Results indicate that the alpha 6(IV) ch ain is expressed in GBM of healthy dogs, but the expression is age-dependen t. Composition and structural organization of type IV collagen in the GBM o f healthy adult dogs is different from that described for other species.