[The radioimmunological assaying of the luteinizing hormone-releasing hormone (LH-RH) in human beings. A general review (author's transl)].

The authors attempted to work out a synthesis of the known factors about the specifications required for the levels of LH-RH and for finding this hormone in different human biological milieux. Searching for endogenous LH-RH in women, men and children has given very different results. The disparity between the levels that have been found, which are often at the very limits of detection by the methods used, can be explained by the type of specification of the level and by the effects of the biological milieu used and by the breakdown of endogenous LH-RH in the living organism.

Characterization of relaxin radioimmunoassay using Bolton-Hunter reagent. First results in plasma during pregnancy, and in placenta, corpora lutea and ovarian cysts in woman.

Application of a porcine relaxin radioimmunoassay system using Bolton and Hunter reagent was characterized in different biological fluids. In pregnant woman, plasma reveals concentrations from undetectable values to 1,800 pg/ml. Maximal concentrations are found between the 8th and the 13th weeks of pregnancy.

Rate of disappearance in plasma of synthetic LH-RH intravenously injected in man.

The rate of disappearance of intravenously injected LH-RH was studied in 6 human volunteers. The blood samples were taken every 20 sec from the time of injection to time +5 min and every 30 sec from time +5 min to time +10 min. The half-life of LH-RH was calculated in the interval of 3-10 min, and was found to be 2.

Radioimmunoassay of LH-RH. Application to human plasma.

Comparison of standard curves with different concentrations of human plasma in the medium of incubation is presented. It appears that Bo varies with the dilution although the ratio B/Bo is independent of the dilution. This last observation was used to research 'endogenous' LH-RH in four menstrual cycles, in postmenopausal women and in men.

Radioimmunoassay of LH-RH. Standard curves and specificity.

As important discrepancies in blood concentrations of LH-RH remain, the basic problem of the specificity of the radioimmunoassay was reinvestigated using an antiserum raised against a new conjugate (33). Cross-reactions with related and unrelated peptides were studied in both charcoal-dextran and second antibody methods of separation. The possible relation between the nature of the conjugate and the specificity is discussed.