Radioimmunoassay of Saliva Estrone Sulfate in Pregnant Sows

抄録

The aim of this study was to establish radioimmunoassay (RIA) for saliva estrone sulfate (E₁S), and to elucidate changes in saliva E₁S during pregnancy in the sow. Saliva E1S was extracted using a commercially available solid phase column, and the E₁S fraction obtained was subjected to RIA. The sensitivity of the RIA was 29.7 pg/tube. The intra-and inter-assay coefficients of variation were 5.5-8.4% and 13.1-19.5%, respectively. Mean recovery for E₁S added to saliva samples was as high as 99.9%. A significant positive correlation (r=0.54, n=69, p<0.01) existed between saliva and plasma E1S concentrations. During gestation, the changing patterns of saliva and plasma E₁S concentrations were essentially the same, and two peaks of E₁S concentrations were observed, one around day 30 and another just before parturition, although E1S concentrations in saliva remained at only 2.4-38.1% (mean 11.4%) of those in plasma E₁S. Thus, the present study has made it possible to measure saliva concentrations of E₁S and demonstrated a high degree of positive correlation between saliva and plasma E₁S concentrations. These results suggest that diagnosis of early pregnancy and of normal or abnormal fetal development could be made by measurements of E₁S in saliva.