Human chorionic gonadotropin

Human chorionic gonadotropin (hCG) is a hormone produced by the placenta after implantation. The presence of hCG is detected in some pregnancy tests (HCG pregnancy strip tests). Some cancerous tumors produce this hormone; therefore, elevated levels measured when the patient is not pregnant may lead to a cancer diagnosis and, if high enough, paraneoplastic syndromes, however, it is not known whether this production is a contributing cause, or an effect of carcinogenesis. The pituitary analog of hCG, known as luteinizing hormone (LH), is produced in the pituitary gland of males and females of all ages.These weight reduction treatments include the injection of HCG, a drug which has not been approved by the Food and Drug Administration as safe and effective in the treatment of obesity or weight control. There is no substantial evidence that HCG increases weight loss beyond that resulting from caloric restriction, that it causes a more attractive or 'normal' distribution of fat, or that it decreases the hunger and discomfort associated with calorie-restrictive diets.There is no scientific evidence that HCG is effective in the treatment of obesity. The meta-analysis found insufficient evidence supporting the claims that HCG is effective in altering fat-distribution, hunger reduction, or in inducing a feeling of well-being. The authors stated “…the use of HCG should be regarded as an inappropriate therapy for weight reduction…” In the authors opinion, “Pharmacists and physicians should be alert on the use of HCG for Simeons therapy. The results of this meta-analysis support a firm standpoint against this improper indication. Restraints on physicians practicing this therapy can be based on our findings.”1hcn: STRUCTURE OF HUMAN CHORIONIC GONADOTROPIN AT 2.6 ANGSTROMS RESOLUTION FROM MAD ANALYSIS OF THE SELENOMETHIONYL PROTEIN1hrp: CRYSTAL STRUCTURE OF HUMAN CHORIONIC GONADOTROPIN1qfw: TERNARY COMPLEX OF HUMAN CHORIONIC GONADOTROPIN WITH FV ANTI ALPHA SUBUNIT AND FV ANTI BETA SUBUNIT Human chorionic gonadotropin (hCG) is a hormone produced by the placenta after implantation. The presence of hCG is detected in some pregnancy tests (HCG pregnancy strip tests). Some cancerous tumors produce this hormone; therefore, elevated levels measured when the patient is not pregnant may lead to a cancer diagnosis and, if high enough, paraneoplastic syndromes, however, it is not known whether this production is a contributing cause, or an effect of carcinogenesis. The pituitary analog of hCG, known as luteinizing hormone (LH), is produced in the pituitary gland of males and females of all ages. Regarding endogenous forms of hCG, there are various ways to categorize and measure them, including total hCG, C-terminal peptide total hCG, intact hCG, free β-subunit hCG, β-core fragment hCG, hyperglycosylated hCG, nicked hCG, alpha hCG, and pituitary hCG. Regarding pharmaceutical preparations of hCG from animal or synthetic sources, there are many gonadotropin preparations, some of which are medically justified and others of which are of a quack nature. As of December 6, 2011, the United States Food and Drug Administration has prohibited the sale of 'homeopathic' and over-the-counter hCG diet products and declared them fraudulent and illegal. Human chorionic gonadotropin is a glycoprotein composed of 237 amino acids with a molecular mass of 36.7 kDa, approximately 14.5 αhCG and 22.2kDa βhCG. It is heterodimeric, with an α (alpha) subunit identical to that of luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), and β (beta) subunit that is unique to hCG. The two subunits create a small hydrophobic core surrounded by a high surface area-to-volume ratio: 2.8 times that of a sphere. The vast majority of the outer amino acids are hydrophilic. beta-hCG is mostly similar to beta-LH, with the exception of a Carboxy Terminus Peptide (beta-CTP) containing four glycosylated serine residues that is responsible for hCG's longer half-life. Human chorionic gonadotropin interacts with the LHCG receptor of the ovary and promotes the maintenance of the corpus luteum during the beginning of pregnancy. This allows the corpus luteum to secrete the hormone progesterone during the first trimester. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. Due to its highly negative charge, hCG may repel the immune cells of the mother, protecting the fetus during the first trimester. It has also been hypothesized that hCG may be a placental link for the development of local maternal immunotolerance. For example, hCG-treated endometrial cells induce an increase in T cell apoptosis (dissolution of T cells). These results suggest that hCG may be a link in the development of peritrophoblastic immune tolerance, and may facilitate the trophoblast invasion, which is known to expedite fetal development in the endometrium. It has also been suggested that hCG levels are linked to the severity of morning sickness or Hyperemesis gravidarum in pregnant women.