The specific binding of parotin on duct cells of human parotid gland.

The relationship between parotin and human parotid gland was investigated using indirect technique of enzyme antibody method. Normal rabbit IgG has non-specific affinity to duct cells of human parotid gland, but it was suppressed by adding bovine serum albumin. Anti-parotin rabbit IgG has no reaction products on the sections of adult human parotid gland. When the sections, initially incubated with parotin solution in PBS, were treated with anti-parotin rabbit IgG containing bovine serum albumin, and then HRPO-labeled anti-rabbit gamma globulin antibodies (swine IgG), intercalated and striated ducts excepting excretory ducts were stained with diaminobenzidine reaction, but also acinar cells did not. These results indicate that parotin is bound specifically on duct cells of human parotid gland.