Hormonal Control and Function of Secretory Proteins
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The uterus of the pig secretes large amounts of protein in response to progesterone. Estrogen alone has little effect but in combination with progesterone is synergistic at low doses and inhibitory at high doses. The responses of the uterus to progesterone require prolonged hormone treatment and are not immediate. The proteins secreted by the uterus of all species are believed to play some role in the nutritional and developmental support of the conceptuses, particularly during early pregnancy. Such a role is likely to be of greater importance in species such as the pig which possesses a noninvasive, diffuse-type of epitheliochorial placentation. A group of basic polypeptides dominates the uterine secretions of the pig. The best characterized is uteroferrin, a purple colored, iron-containing acid phosphatase which transports iron across the placenta. Three polypeptides which are found associated noncovalently with uteroferrin have been shown to be antigenically closely related to each other and to have arisen from a single precursor polypeptide. Their function is unknown. A family of plasmin/ trypsin inhibitors which show sequence homology with bovine pancreatic trypsin inhibitor (aprotinin) has been well characterized and appears to control intrauterine proteolytic events initiated by the conceptuses. Several other proteins secreted in response to progesterone remain to be characterized and functionally defined.
KeywordsEstrous Cycle Bovine Pancreatic Trypsin Inhibitor Estradiol Valerate Uterine Lumen Pregnant Uterus
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- 1.E. C. Amoroso, Placentation, in; “Marshall’s Physiology of Reproduction,” E. Parks, ed., Longman’s Green, London, 127–311, (1951).Google Scholar
- 2.E. S. E. Hafez and M. K. Jainudeen, Gestation, prenatal physiology and parturition, in: “Reproduction in Farm Animals,” E. S. E. Hafez, ed., Lea and Feibiger, Philadelphia, 143–145 (1974).Google Scholar
- 6.R. M. Roberts and F. W. Bazer, The properties, function and hormonal control of synthesis of uteroferrin, the purple protein of the pig uterus, in: Steroid Induced Uterine Proteins, M. Beato, ed., Elsevier/North Holland, Amsterdam, 133–149 (1980).Google Scholar
- 7.M. Frank, F. W. Bazer, W. W. Thatcher, and C. J. Wilcox, A study of prostaglandin F2 as the luteolysin in swine: III Effects of estradiol valerate on prostaglandin F, progestins, estrone and estradiol concentrations in the utero-ovarian vein of non-pregnant gilts, Prostaglandins 14: 1183–1196 (1977).PubMedCrossRefGoogle Scholar
- 10.R. M. Roberts, T. J. Raub, and F. W. Bazer, Role of uteroferrin in transplacental iron transport in the pig, Fed. Proc. 45: 2513–2518 (1986).Google Scholar
- 11.R. M. Roberts and F. W. Bazer, Uteroferrin: a protein in search of a function, Bio Essays 1: 8–11 (1984).Google Scholar
- 12.B. C. Antanaitis and P. Aisen, Uteroferrin and the purple acid phosphatases, in: “Advances in Inorganic Biochemistry,” Vol. 7, “Iron Binding Proteins,” E. C. Theil, G. C. Eichorn, and L. Marzilli, Elsevier, New York, 111–136 (1983).Google Scholar
- 14.P. T. K. Saunders, R. H. Renegar, T. J. Raub, G. A. Baumbach, P. H. Atkinson, F. W. Bazer, and R. M. Roberts, The carbohydrate chains of porcine uteroferrin and the role of the high mannose chains in promoting uptake by the reticuloendothelial cells of the fetal liver, J. Biol. Chem. 260: 3658–3665 (1985).PubMedGoogle Scholar
- 22.H. Fritz and G. Wunderer, Biochemistry and applications of aprotinin, the kallikrein inhibitor from bovine organs, Arzneim Forsch. Drug Res. 33: 479–496 (1983).Google Scholar
- 26.R. C. M. Simmen, M. H. Wilde, W. F. Pope, and f. A. Simmen, Porcine uterine luminal fluid contains epithelial cell growth stimulating factors, J. Cell Biol. 103:154a, Abstr. 565 (1986).Google Scholar