Abstract
Josimovich and MacLaren (1962) demonstrated a substance which cross-reacted immunologically with rabbit antiserum to growth hormone (HGH). This is the first report to arouse a widespread interest in this protein. The purpose of this report was to investigate the cross-recation of HGH and human chorionic gonadotropin (HCH) with anti-HPL serum, and to investigate our crude HPL extracted from placenta immunologically..
Antiserum to HPL was prepared in guinea pigs using the partically purified HPL. Antiserum to HCG was prepared in rabbits using the HCG (5127 IU/mg). Antiserum to human serum was kindly supplied by the Department of Clinical Laboratory, Otsu Red Cross Hospital. Various hormones used in this report were NIH-HGH, partially purified HPL, highly purified HPL, HCG (5127 IU/mg) and our crude HPL which was extracted from placenta. The method of Ouchterlony was carried out in Petri dishes. The immunoelectrophoresis was performed on glass slides for 60 minutes at 100 V, 3 mA/cm with veronal buffer pH 8.6.
The cross-reaction of HGH with antiserum to HPL was revealed in the present studies. These immunological studies using the anti-HPL serum - HGH system were reversely confirmed that HPL cross-reacted with antiserum to HGH, as reported by Josimovich et al. and other workers. No precipitation line was detected between antiserum to HPL and 2000μg/ ml-100pg/m1 solution of HCG. The reaction of 2000 μg-100 pg/ml solution of HPL or HGH with antiserum to HCG resulted in the formation of no precipitation line. Although HPL is secreted from placenta as well as HCG, immunologically HPL is similar to HGH but not to HCG. This relationship between HGH and HPL appears to be comparable to that between pituitary luteinizing hormone and HCG. In immunoelectrophoresis, the precipitation line formed by the reaction with HPL was migrated to the more anode side than the precipitation line reacted with HGH. When male human serum was reacted with antiserum to HPL, three lines of preicpitation were observed in the γ-globulin, neutral and albumin regions. These non-specific antibodies appear to be purified by absorption with human serum. The reaction of our crude HPL with antiserum to HPL resulted in three lines of precipitation, a line of precipitation in the a-globulin region which appeared to represent the HPL and two lines of percipitation in the γ-globulin and albumin regions which appeared to be human serum components. The crude HPL reacted with antiserum to human serum formed three precipitation lines in the γ-globulin, neutral and albumin regions. The authors' extraction method of HPL from human placenta appears to be satisfactory.
In order to reveal the properties of HPL in normal pregnancy, there arises a demand to purify HPL. We shall experiment purification of HPL.
