Summary. Pregnancy-associated murine protein 1 (PAMP-1) was present in the circulation of all mice at 1-day of age but not at Days 2–20. PAMP-1 values were low in juvenile male mice during puberty but had reached normal adult female levels within 35 days of birth in females. Concentrations in castrated males were similar to those of non-pregnant females within 6 weeks of operation. Testosterone treatment of castrated males and sexually mature females, and ovariectomy of adult females resulted in a significant fall in PAMP-1 concentrations. It is concluded that PAMP-1 is sex-steroid dependent.
J. Hau, P. Svendsen, B. Teisner and J. G. Grudzinskas
J. Hau, P. E. Svendsen, B. Teisner and S.-E. Svehag
Summary. A pregnancy-associated murine protein (PAMP) with α1 electrophoretic mobility and an estimated molecular weight of 140 000 was present in serum from pregnant and sexually mature non-pregnant females, but could not be detected in the serum of males. During pregnancy the serum concentration of α1-PAMP rose to a maximum in mid-pregnancy followed by a decline to preconception levels before parturition; the protein was also present in fetal and neonatal serum and in amniotic fluid at low concentrations.
J. Hau, P. Svendsen, B. Teisner and G. Thomsen Pedersen
Summary. The glycoprotein structure of two pregnancy-associated murine proteins, α1-PAMP and α2-PAMP, was analysed by using concanavalin A (Con A) affinity electrophoresis: α1-PAMP was completely precipitated by free Con A, whereas α2-PAMP showed heterogeneity. The isoelectric points of α1-PAMP and α2-PAMP were determined at 4·2 and 4·0 respectively by using crossed immunoelectrofocusing. The α2-PAMP was detectable only in the serum of pregnant mice and fetuses. Maternal serum concentrations increased from Day 8 of pregnancy, remained at high values between Days 14 and 18, and could not be detected by 2 days post partum.
J. G. Westergaard, A. Bach, B. Teisner, J. Hau and J. G. Grudzinskas
Summary. Women with twin pregnancies were matched with those carrying singleton pregnancies (n = 35 for both) for features which are considered to influence pregnancy zone protein (PZP) concentrations. The mean PZP level was significantly lower (P < 0·01) and the mean total oestriol level was higher (P < 0·001) in twin than in singleton pregnancies. PZP levels were negatively correlated to oestriol levels in twin (r = −0·5756, P < 0·001) and singleton (r = −0·3821, P < 0·01) pregnancies.
A. A. Gidley-Baird, B. Teisner, J. Hau and J. G. Grudzinskas
Summary. An antiserum against the serum of a pregnant mare was absorbed with stallion serum. This antiserum then gave two precipitates in crossed immunoelectrophoresis with serum from pregnant mares as the antigen. The two precipitates exhibited beta-1 and alpha-2 electrophoretic mobility. Identity was demonstrated between the alpha-2 mobile protein and PMSG. The absorbed antiserum inhibited the biological action of the PMSG preparation when tested in mouse ovarian weight assays. The beta-1 mobile protein was not detected in the serum from non-pregnant mares, stallions or geldings and was detected earlier in pregnancy (Day 30) than was PMSG (Day 42).
J. Hau, J. G. Westergaard, P. Svendsen, Annelise Bach and B. Teisner
Summary. Immunological cross-reaction between human pregnancy-specific β1-glycoprotein (SP-1) and pregnancy-associated murine protein-2 (α2-PAMP, PAMP-2) was demonstrated by line immunoelectrophoresis using antibodies against the proteins raised in hens. The pattern of change of PAMP-2 and SP-1 values in serum during pregnancy was very similar. The murine placental growth-rate corresponded to PAMP-2 levels in maternal serum during pregnancy, indicating placental origin.
We suggest that the mouse and its PAMP-2 can be used to study human SP-1.
N. Fröhlander, A. A. Gidley-Baird, J. Hau and B. von Schoultz
Summary. In male mice which normally do not synthesize measurable amounts of the pregnancy-associated murine protein-1 (PAMP-1), synthesis occurred when there was continuous infusion of hGH but not by repeated subcutaneous injections. The decrease in PAMP-1 values after hypophysectomy in female mice was rapidly restored by continuous infusion of hGH, 80 μg daily. PAMP-1 has generally been regarded as an 'oestrogen-inducible' protein regulated by the oestrogen/androgen balance. Our results suggest that the apparent effects of sex steroids are mediated via the pituitary and possibly growth hormone secretion.