DITHIOTHREITOL TREATMENT PERMITS MEASUREMENT OF MELATONIN IN OTHERWISE UNUSABLE SALIVA SAMPLES

Melatonin research has primarily utilized blood as the source of sampl es, but there is now increasing interest in measuring levels of the ho rmone found in saliva. One impediment to this approach is that several melatonin assays involve a column-extraction step that can prove very time-consuming or even impossible when salivary samples are excessive ly viscous. We have treated 67 samples with dithiothreitol to enhance their passage through the column. Following this treatment, all sample s passed freely through the columns. The minimum and maximum values me asured were 0.7-50.0 pg/ml for the untreated controls and 1.0-51.9 pg/ ml for the treated samples. The means (+/- SEM) for these groups were 9.5 +/- 1.6 and 9.9 +/- 1.7, respectively, and were not significantly different from one another as assessed by Student's t-test (P = 0.08). In summary, we have found that this technique permits us to obtain va lues on samples which would otherwise be unusable and that such treatm ent does not alter the melatonin values yielded by RIA analysis.