Evidence for receptor-mediated uptake of adenosine deaminase in rabbit kidney.
We investigated the subcellular location of adenosine deaminase-complexing protein in the proximal renal tubules of rabbit kidney and its interaction with intravenously infused monomeric calf adenosine deaminase. Cortical tissue from non-infused animals, stained in suspension by the peroxidase-antiperoxidase method for complexing protein and embedded in resin, was examined by transmission electron microscopy. Positive staining indicated the presence of complexing protein on the surface of microvilli in the proximal tubules. Sections (1 micron) of resin-embedded cortex from infused rabbits, stained first for complexing protein and then for adenosine deaminase, were examined by light microscopy. After staining for complexing protein by indirect immunofluorescence, the sections were photographed and then immersed in buffer containing 6 M guanidine hydrochloride plus 2-mercaptoethanol for 3 hr at 60 degrees C to remove bound antibodies. The sections were then stained by the peroxidase-antiperoxidase method for infused enzyme. Vesicle-like apical structures, the basal membrane area and, as previously reported, the brush border of proximal tubule cells were positive for complexing protein. Vesicle-like structures and brush borders positive for complexing protein were also stained for adenosine deaminase. The basal membrane area did not stain. These results support the hypothesis that complexing protein can act as a receptor for adenosine deaminase.
Schrader
W P
WP
Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12201.
Miczek
A D
AD
West
C A
CA
Samsonoff
W A
WA
D000243:Adenosine Deaminase / Q000378:metabolism* / Q000652:urine; D000818:Animals; D002417:Cattle; D005260:Female; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000378:metabolism*; D006651:Histocytochemistry; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000201:enzymology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008871:Microvilli / Q000201:enzymology; D009700:Nucleoside Deaminases / Q000378:metabolism*; D011817:Rabbits; D013194:Staining and Labeling
D006023:Glycoproteins; D007527:Isoenzymes; C489010:adenosine deaminase-complexing protein, Oryctolagus cuniculus; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase