Lactogen, human placental

Chorionic Somatomammotropin. Three genes encode human chorionic somatomammotropin [11085-36-2] (hCS). These are located within a cluster of genes on human chromosome 17 which code for pituitary growth hormone [12629-01 -5] (GH-N), placental GH [109675-94-7J (GH-V), and three hCS molecules, ie, hCS-A, hCS-B, and hCS-V (1 3), also referred to as human placental lactogens. All of these molecules ate closely related to GH in stmcture (Fig. 1). Placental lactogens also exist in rodents and mminants however, these hormones are more closely related to prolactin than GH. 

Barbour, H.M. (1976) Development of an enzyme immunoassay for human placental lactogen using labelled antibodies./. Immunol. Meth. 11, 15. 

Morphologically, this is demonstrated by the development of a multinuclear syncytium with apical microvilli [49], while functional differentiation is associated with induction and synthesis of hormones, such as human chorionic gonadotropin (hCG) and human placental lactogen (hPL) [50, 51]. Cultures of primary cytotrophoblasts have been used to study functional expression of P-gp, amino acid uptake, and hormonal stimulation of amino acid uptake and... 

R.G. Richards, S.M. Hartman, and S. Handwerger. Human cytotrophoblast cells cultured in maternal serum progress to a differentiated syncytial phenotype expressing both human chorionic gonadotropin and human placental lactogen. Endocrinology. 135 321-329 (1994). 

Along this line Matsue et al. [37,45,78,79] have developed a number of biochips. Among them are multi-analyte assays for human placental lactogen (HPL) and human chorionic gonadotropin (HCG) [45] and leukocidin, a toxic protein produced by methicillin-resistant Staphylococcus aureus [79]. Figure 37.8 shows an example of a dual immunoassay with SECM detection. The analyte is defined by the position on the chip and the amount of analyte is quantified via the collection current at the UME. The current originates from the reduction of ferrocinium methanol (Fc+) at the UME. Fc+ is produced locally at the chip surface by the enzyme HRP under consumption of H202. 

Macromolecular substances with multiple antigenic determinant [Ag] can be determined by agglutination of particles which are coated with specific antibodies [Pa-Ab Ag Ab-Pa]. This method can detect immunoglobulins, human placental lactogens, a-fetoprotein, etc. The sensitivity is approximately 10 (xg/liter. Alternatively, antigen-coated particles are used these particles agglutinate with antibodies. Thus, antibodies can be determined by this system. Cambiaso et al. reported automated determination of immune complexes by their inhibitory effect on the agglutination of IgG-coated particles by rheumatoid factor or Clq (C3). 

The automated system of the particle counting immunoassay is now commercially available as the product impact (Immunoassay by Particle Counting), which can measure C-reactive protein, ferritin, human placental lactogen, thyroxine, a-fetoprotein (C7), IgE (M2), digoxin (C6), somatotropin (C5), and others. 

Lowman, H. B., Cunningham, B. C., and Wells, J. A. (1991b). Mutational analysis and protein engineering of receptor-binding determinants in human placental lactogen./ Biol. Chem. 266, 10982-10988. 

Sciarra JJ, Sherwood LM, Varma AA, Lundberg WB. Human placental lactogen (HPL) and placental weight. Am J Obstet Gynecol 1968 101 413-6,... 

Anterior pituitary hormones are classihed into three families the somatomammotropin family (GH and PRL), the glycoprotein hormones (LH, FSH, and TSH), and the opiomelanocortin family (ACTH, /i-endorphin, and related peptides). These three families appear to have evolved from three separate ancestral polypeptides homologous members of each family occur in other parts of the body. For example, human placental lactogen (hPL) is somatomammotropic, human chorionic gonadotrophin (hCG) is a glycoprotein hormone, and the brain and gut produce substances related to endorphins (enkephalins and dynorphin). 

A variant of the sequential method (Belanger et al., 1976 Van Weemen et al., 1978), which is routinely used for human placental lactogen and oestrogens, is as follows (3 steps) ... 

H Shiku, Y Hara, T Matsue, I Uchida, T Yamauchi. Dual immunoassay of human chorionic gonadotropin and human placental lactogen at a micro-fabricated substrate by scanning electrochemical microscopy. J Electroanal Chem 438 187-190, 1997. 

Human placental lactogen (HPL) is a 22-kD protein with partial homology to growth hormone. HPL is secreted by syncytiotrophoblastic cells in choriocarcinoma and intermediate trophoblasts in a testicular trophoblastic tumor that is a counterpart to a uterine placental site trophoblastic tumor. 

This lesion, actually an exuberant, non-neoplastic physiologic hnding that frequently accompanies molar pregnancies, is composed mostly of implantation site intermediate trophoblasts. The constituent cells express human placental lactogen (hPL) and HLA-G. The Ki-67 index in an exaggerated placental site reaction is less than 10% to 15%.2 ... 

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