Harutake Sakura

Simultaneous determinations of plasma oxytocin and serum placental leucine aminopeptidase (P-LAP) during late pregnancy

1. Plasma oxytocin concentrations were measured by radioimmunoassay in 231 normal pregnant patients. The mean level of the maternal plasma oxytocin increases gradually with advancing pregnancy, culminating in a marked increase during the last two months. 2. Serum placental leucine aminopeptidase (P-LAP) activities and oxytocinase were measured serially in 78 obstetrically normal pregnant patients during late pregnancy. The daily mean P-LAP activity rises progressively during late pregnancy, reaching a relatively high level at 11 days prior to the onset of labor, then fluctuates slightly until the onset of labor. 3. Simultaneous serial measurements of plasma oxytocin levels and serum P-LAP activities in 9 normal pregnant women during late pregnancy show that the onset of labor is preceded by either an increase in the oxytocin level or a decrease in the P-LAP activity.

A comparison of angiotensinase and placental leucine aminopeptidase during normal pregnancy.

1. Serum leucine aminopeptidase activity measured by its action on hydrolysis of L-leucyl-beta-naphthylamide was increased progressively as pregnancy advanced. Angiotensinase activity determined by bioasaay showed parallel increase during normal pregnancy. 2. The effects of heat treatment and L-methionine on the activity of angiotensinase were compared with those on leucine aminopeptidase activity in pregnancy serum.

Large glucagon-like immunoreactivity in a primary ovarian carcinoid.

A primary ovarian carcinoid composed of both trabecular and strumal types was studied by histochemical, immunocytochemical, and biochemical techniques. High contents of glucagon, secretin, and calcitonin were demonstrated in the tumor homogenate. All of the tumor cells, irrespective of histologic type, showed properties of argyrophilia and neurosecretory granules on electron microscopy. Glucagon‐producing cells were positive in trabecular carcinoid by immunoperoxidase techniques. Bio‐Gel P10 gel filtration showed that the molecular weight of major immunoreactive glucagon in tumor was 20,000. It migrated faster than true glucagon after polyacrylamide gel electrophoresis. No clinical symptoms of glucagonoma developed.

Oxytocinase-like enzyme in an ovarian dysgerminoma: A placenta-specific protein

Aminopeptidase from dysgerminoma was purified and characterized using L-leucine-beta-naphthylamide as substrate. The enzyme was resistant to puromycin, methionine, amastatin, bastatin, and EDTA, and it was heat labile at 60 degrees C. The enzyme showed the same electrophoretic mobility as pregnant-patient serum oxytocinase CAP1 on polyacrylamide gel electrophoresis. Km value against S-benzylcysteine-p-nitroanilide was 4.2 X 10(-4) M. Oxytocin and vasopressin competitively inhibited the enzyme activity. Molecular weight of the enzyme was estimated to be 80,000 by Sephadex G-200 column chromatography. These results suggest that aminopeptidase from dysgerminoma is an oxytocinase-like enzyme, a placenta-specific protein.

Occurrence of an anti-peplomycin IgE antibody cross-reacting with bleomycin in a patient with cervical uterine cancer

SummaryAn allergic reaction to peplomycin was observed in a patient with cervical uterine cancer who had previously been treated with peplomycin. A positive Prausnitz-Küstner test and its elimination after heat treatment of the serum showed the production of anti-peplomycin IgE antibody. Peplomycin was coupled to a paper disc and a sensitive radioallergosorbent test for peplomycin was developed to quantitate the antibody. Patient serum IgE and IgG were purified by DE52 column chromatography; the IgE fraction contained binding activity to peplomycin. A competition test revealed that the antibody bound to both peplomycin and bleomycin. DNA, RNA, and mononucleotides had no effect on antibody binding, but the antibody inhibited peplomycins activity.