Expression of the alpha6 chain of type IV collagen in glomerular basement membranes of healthy adult dogs.

ABSTRACT

OBJECTIVE: To evaluate expression of the alpha6 chain of type IV collagen in the glomerular basement membranes (GBM) of healthy dogs. SAMPLE POPULATION Kidney specimens from 12 healthy dogs. For comparison, kidney specimens from 8 human subjects between 25 and 83 years old also were evaluated. PROCEDURE Sections were immunolabeled with a monospecific antibody that cross-reacts with human and canine alpha6(IV) chains and examined by means of fluorescence microscopy. RESULTS: Immunolabeling of the alpha6(IV) chain was not observed in GBM of 6 dogs < or = 30 months old but was observed in GBM of the remaining 6 dogs, all of which were > or = 45 months old. Expression of the alpha6(IV) chain was not observed in GBM of the human subjects, regardless of the age of the subject. CONCLUSIONS AND CLINICAL RELEVANCE Results indicate that the alpha6(IV) chain is expressed in GBM of healthy dogs, but the expression is age-dependent. Composition and structural organization of type IV collagen in the GBM of healthy adult dogs is different from that described for other species.