A radioimmunoassay for 5alpha-androst-16-en-3-one in porcine adipose tissue.

A simple and reliable radioimmunoassay (RIA) for the estimation of 5alpha-androstenone (5alpha-androst-16-en-3-one) in porcine adipose tissue has been developed. Fatty tissue samples weighing 40-60 mg were used for assay. The bulk of fat was separated from the steroid by centrifugation in an ethylacetate-ethanol solution at about -70 degrees C. The sensitivity of the standard curve was found to be 25 pg (P smaller than 0.01) and the smallest amount of 5alpha-androstenone added to adipose tissue from castrated male pigs, that can be estimated by the method, is 0.09 mug/g. Analysis of the data from the accuracy study gave the regression line y equals 1.09 times + 2.7. The mean coefficients of variation for the inter- and intra-assay precision were 11.1 and 5.9%, respectively. In boars (n equals 9) a mean value of 2.09 mug/g adipose tissue was found (SD equals 2.56). In adipose tissue from 9 female pigs and 8 castrated male pigs the level of 5alpha-androstenone was found to be undetectable by the present method. In adipose tissue from one castrated male pig trace amounts of 5alpha-androstenone were found.