[Radioimmunoassay in the testing of new pharmacological agents]

The activity of Parathorm, a pharmaceutical obtained from parathyroid hormone (PTH), was studied. Human blood plasma proteins as well as bivalent anions have been shown to produce a negative effect on the antigen-antibody interaction. The proportion of the PTH-protein complexes with the elevation of the pharmaceutical dose is constant in many concentrations whereas with the elevation of the PTH dose the PTH-low molecular complexes account for ever increasing proportion of the radioactive complexes.