Technische Universität München

The Entrepreneurial University

Hormones realize the endocrine regulation of the body functions. They are chemical messengers produced by the endocrine glands and/or endocrine cells in other organs (kidney, heart, etc.) whose secretions are released directly into the bloodstream and transported to the target cells where the hormones, after binding to protein cell’s receptors, exert their specific effects. The main endocrine glands in the body are the pituitary (hypophysis), thyroid, parathyroid, and adrenal glands, the pancreas, ovaries, and testes. The hypothalamus is a major part of CNS, but it also produces hormones and is considered a neuroendocrine organ. The hypothalamus has a direct vascular connection with the anterior pituitary - the hypothalamic neural cells secrete into this portal circulation several releasing and inhibiting hormones that regulate hypophyseal secretion. Each of the primary anterior pituitary hormones has a hypothalamic releasing hormone, often called a releasing factor (gonadotrophin-releasing hormone stimulates the secretion of both anterior pituitary gonadotrophins, luteinizing hormone and follicle-stimulating hormone).  

The following hormones and their releasing factors as well as other substances with similar chemical structure or similar biological effects are prohibited.  
  1. Erythropoietin (EPO) is a glycoprotein hormone released from the kidneys (85%) and liver (15%); the secretion of EPO is stimulated by hypoxia.
  2. Human growth hormone (hGH) is a peptide hormone secreted by the anterior pituitary gland. The hypothalamic growth hormone-releasing hormone (GHRH) and probably ghrelin stimulate hGH secretion. Besides its other direct effects on target cells hGH also stimulates the synthesis of insulin-like growth factor 1 (IGF-1) in all tissues. In most tissues IGF-1 has local actions, but liver secretes it into the circulation. Mechano growth factor (MGF) is derived from the IGF-1 gene by alternative splicing and is expressed in skeletal muscles.
  3. The gonadotrophins that are prohibited in males only are the luteinizing hormone (LH) and human chorionic gonadotrophin (hCG). LH is a glycoprotein secreted by the anterior pituitary gland, which regulate the secretory and gametogenic functions of the testes and ovaries. The hypothalamic gonadotrophin-releasing hormone (GnRH) stimulates the secretion of the LH. Human chorionic gonadotrophin (hCG) is a placental hormone. Its presence in the plasma and urine is one of the earliest signals of pregnancy and the basis of pregnancy tests. Small amounts of hCG are also secreted by a variety of tumours in both sexes (tumour marker).  
  4. Insulin is secreted by the β-cells of the islets of Langerhans in the endocrine pancreas; it mainly acts on carbohydrate, fat and protein metabolism. It is permitted only to treat athletes with certified insulin-dependent diabetes mellitus.  
  5. Corticotrophin (adrenocorticotrophic hormone, ACTH) is produced in the anterior pituitary gland and regulates the secretion of the steroid hormones from the adrenal cortex. Under the effects of various stressors hypothalamus secretes corticotrophin-releasing hormone (CRH), which stimulates releasing of ACTH.