[Radioimmunologic technics for luteinizing hormone determination in cattle and sheep].

The antigen relationship which exists between luteinising hormone of various animal species, on the one hand, and human luteinising hormone as well as human chorionic gonadotrophin, on the other, was the background against which possible approaches were tested to the preparation of a heterologous in-vitro test for serum LH determination in cattle and sheep. The following conclusions may be drawn from the results so far obtained: --A homologous or heterologous test with specific relevance to the determination of human LH, on the basis of hLH-anti-hLH or hLH-anti-hCG is not suitable for the determination of LH in animal serum (cattle, sheep). --Quantitative and specific measurement of LH concentrations in the blood of cattle (sheep) is possible by means of an ovine-LH-anti-ovine/bovine-LH (or anti-bovine-LH) test system which is based on cross-reactivity between luteinising hormones of cattle and sheep. --Differentiated measurement of various LH concentrations in animal serum will be possible under certain specific assay conditions, with ovine LH as tracer, ovine or bovine LH as standard, and hCG antiserum. Yet, the clinical value of that heterologous radio-immuno-assay method is attributable primarily to its potential to measure peak values within the cycle to determine the time of ovulation rather than to the built-in possibility to determine base values of the cycle.