Stability of human lutropin studied with immunoenzymatic technique.

Characteristics of two monoclonal antibodies against human lutropin and their use in enzyme immunoassays of the hormone are presented. Diluted solution of pituitary lutropin was unstable in buffered saline and could be stabilized with some proteins. Concentration of the lutropin in woman urine, collected during "lutropin-peak", was markedly increased during long time storage at 5 degrees C or at room temperature. Using HPLC it was demonstrated that pituitary lutropin, normal urine lutropin and "increased" urinary lutropin were eluted from ion exchange column almost with the same retention time.