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  • Author: A. A. Gidley-Baird x
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J. P. Hearn, G. E. Webley and A. A. Gidley-Baird

Summary. Genes for chorionic gonadotrophin (CG) are transcribed by the 16-cell embryo stage in humans, but there is no clear evidence of CG secretion as a bioactive dimer before attachment and trophoblast outgrowth stages of implantation. The studies summarized question the timing of CG expression and secretion, the possible roles of CG for intraembryonic differentiation and at the implantation site, and the recognition of this primate embryo-derived signal in support of the corpus luteum. The data suggest that the implantation window in primates may be broader than in nonprimate species, where a closer synchrony between embryonic, tubal and uterine events appears to be necessary for embryonic survival. Some preliminary data concerning an association between peripheral thrombocytopenia, ovarian inhibin secretion and peri-implantation stages of embryo development indicate that an unknown embryonic signal may be secreted before bioactive CG can be detected.

Keywords: chorionic gonadotrophin; corpus luteum; embryo; implantation; platelet-activating factor; inhibin; pregnancy; primate

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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).

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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.