RADIOIMMUNOASSAY FOR SALIVARY CARBONIC-ANHYDRASE IN HUMAN PAROTID-SALIVA

A specific radioimmunoassay for human carbonic anhydrase (CA) VI has b een developed and used to determine the concentrations of the enzyme i n saliva. The assay detected as little as 200 pg of CA VI and the anti body used hid not cross-react with CA II or other salivary proteins. T he method showed an intra-assay Variation of 8.5% and an inter-assay v ariation of 16.9%. The concentration in parotid saliva varied over a w ide range (from 9.7 mu g/ml to 121 mu g/ml) with an average value of 4 7.0 +/- 39.2 (SD)mu g/ml (n = 50). The mean secretion rate of CA VI fr om the combined parotid glands was 42.8 +/- 37.9 mu g/min. CA VI repre sented about 3% of the total protein in parotid saliva.