Separation of SP1 alpha and SP1 beta on hydroxylapatite

The concentrations of SP1 beta and SP1 alpha in retroplacental and peripheral blood at term

The concentrations of the two components of Schwangerschaftsprotein 1 (SP1 beta and SP1 alpha), human chorionic gonadotrophin (hCG) and human placental lactogen (hPL), were measured in peripheral venous blood and in retroplacental blood at term delivery in 22 women. Like hCG and hPL, the values of SP1 alpha were higher in the retroplacental than in the peripheral blood, as might be expected with placental secretory products. On the other hand, the concentration of SP1 beta showed a reverse gradient, being higher in the peripheral than in retroplacental blood.

Diagnosis of early pregnancy by assay of placental proteins

The plasma concentrations of Schwangerschaftsprotein 1 (SP1) and human chorionic gonadotrophin (hCG) were measured in 22 women before and after conception. In these pregnancies ovulation occurred spontaneously in seven subjects, or followed treatment with either clomiphene citrate (6 subjects), or human menopausal gonadotrophin (hMG) and hCG (6 subjects). The remaining three patients became pregnant after artificial insemination with donor semen. Seventeen of these pregnancies were normal and five were abnormal (3 abortions, 1 ectopic and 1 twin). SP1 could be detected 6-14 days after ovulation in all these patients. In contrast 40 non-pregnant women gave a negative test for SP1.

Complex formation of pregnancy-specific alpha 2-glycoprotein (SP1 alpha) and heparin

The Schwangerschaftsprotein 1 (SP1)alpha values in blood measured by rocket immunoelectrophoresis are affected by the addition of anticoagulants. When compared with values in serum, those in heparin plasma were much higher, while those in sequestrene ethylenediamine-tetra-acetic acid), sodium citrate and fluoride oxalate were lower. On the other hand, SP1 and SP1 beta concentrations were not significantly affected in heparin or sequestrene and were only slightly depressed in sodium citrate and fluoride oxalate. The effect of heparin on SP1 alpha in serum was dose-dependent. We surmise that SP1 alpha forms a complex with heparin and that it may be involved in the coagulation system in pregnancy.