Endocrinology of pregnancy: chorionic somatomammotropins and pregnancy-associated glycoproteins: review.

This research paper discusses two main groups of placental proteins in ruminants: chorionic somatomammotropins and pregnancy-specific proteins. Their secretion, participation in mammogenesis, fetal growth and maternal metabolism, as well as their endocrine function, particularly in relation to trophoblastic function disorders and equine and primate placenta, are examined.

Chorionic Somatomammotropins and Pregnancy-Specific Proteins

• The main focus of the paper is two specific groups of placental proteins found in ruminants: chorionic somatomammotropins (otherwise known as placental lactogens) and pregnancy-specific proteins.
• Placental lactogens are part of the prolactin and growth hormone families, which are known to stimulate mammogenesis (formation of mammary glands), fetal growth and alterations in maternal metabolism during pregnancy.
• Pregnancy-specific proteins and pregnancy-associated glycoproteins, on the other hand, are members of the aspartic proteinase family, like pepsin, cathepsin D and E which are digestive enzymes.

Secretion of Proteins

• The study details how these protein groups are secreted into the maternal circulation by binucleate cells after their migration to and fusion with the uterine cells.
• The secretion profiles of these proteins are determined using radioimmunoassay (RIA), a laboratory method used for measuring concentrations of antigenic proteins.

Correlation with Trophoblastic Function

• Investigations are being conducted on the correlation between the secretory profiles of these protein groups with alterations in the trophoblastic function. Trophoblastic function refers to the role of trophoblasts, a layer of cells in the blastocyst helping to provide nutrients to the embryo and develop into a large part of the placenta.
• Particular focus is on changes occurring in embryonic mortality, abortion, and fetal distress.

Endocrine Function of Primate and Equine Placenta

• The paper also discusses the endocrine functions of the primate and equine placenta. The endocrine system helps control body functions through the production and secretion of hormones. In the case of placenta, it plays a crucial role during pregnancy by producing hormones necessary for the maintenance of pregnancy and the development of the fetus.