DEVELOPMENT OF A RADIOIMMUNOASSAY FOR 5α-ANDROST-16-EN-3-ONE IN PIG PERIPHERAL PLASMA

Abstract

ABSTRACT A radioimmunoassay (RIA) for 5α-androst-16-en-3-one (5α-androstenone) in peripheral plasma from pigs has been developed. Antibodies against 5α-androstenone conjugated through C-3 to bovine serum albumin (BSA) were produced in rabbits. The antiplasma used in this study show a cross-reaction of 100% with 4,16-androstadien-3-one (androstadienone), 5.3 % with 5α-androst-16-en-3β-ol (an-β), 3.3 % with 5α-androst-16-en-3α-ol (an-α), 2.6 % with 4-androstene-3,17-dione (androstenedione) and 1.4% with 5,16-androstadien-3β-ol (andien-β). The standard curve plotted as log picogram (pg) unlabelled 5α-androstenone against counts per minute (cpm) bound radioactive steroid was almost linear from 50 to 800 pg 5α-androstenone. Regression analysis of the data from the accuracy study gave the curve y = 0.99 x+ 203. The precision and sensitivity of the method were satisfactory. In plasma samples from sows and castrated male pigs the mean 5α-androstenone found was 1.1 ng/ml. In plasma samples from boars from 1.2 to 54.1 ng/ml was found.