[A study on the immunoreactive luteinizing hormone-releasing hormone in villi by radioimmunoassay in the first trimester (author's transl)].

We extracted the immunoreactive luteinizing hormone-releasing hormone (IR-LHRH) from villous and plasma in the first trimester of pregnancy with 0.2N acetic acid and the florisil absorbtion method. Recovery rate was 40.0 +/- 4.08% in the former and 62.5 +/- 9.5% in the latter, respectively. These IR-LHRH were measured by radioimmunoassay, which showed sensitivity from 5 to 500 pg/ml. The villous IR-LHRH was compared with synthetic LH-RH by a dilution curve in different concentrations and the column gel filtration of sephadex-G25. The dilution curve of synthetic LH-RH and sample material showed a significant correlation, and the elution time of villous IR-LHRH on the column was something faster than that of synthetic LH-RH. The concentration of villous IR-LHRH showed 20--100 pg/0.1g dry weight in the first trimester of pregnancy, and the peak was at 9 weeks of normal pregnancy and at 8 weeks of inevitable abortion respectively, but these IR-LHRH levels were not changed between pre- and post-dilation and curettage. From this evidence, we considered that IR-LHRH show activity of the local hormone in villous tissue similar to somatostation.