Abstract
Fundamental and practical problems in carrying out the radioimmunoassay of gastrin were studied by comparing the double antibody method using guinea pig anti-porcine gastrin serum (Wilson Lab.) with the gastrin kit method (G-K, CIS). The former method was found to have the range of measurable gastrin concentration between 60 and 1, 000pg/ml, wheras the range of the latter method was between 25 and 800pg/ml. Both methods were found to have satisfactory reproducibilities. The G-K method was, when compared with the double antibody method, found to be affected more readily by co-existing proteins, whereas the interferences by other biologically active factors, e.g., CCK/PZ, caerulein, etc., were negligible. While there was a highly significant correlation between the values obtained by the two methods (r=0.86, P<0.001), the values obtained by the G-K method were generally slightly lower than the values obtained by the double antibody method. The fractionation analysis employing the gel filtration of blood and tissue immunoreactive gastrin resulted in theobservation that the value of "big gastrin" as determined with the G-K method was lower thanthat obtained by the double antibody method, and that the difference was especially remarkable for gastrin in blood.
