Localisation of gonadotropin-releasing hormone in the circumventricular organs of human brain
| Autor: | Yitschak Koch, Elimelech Okon |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Adult
Male endocrine system medicine.medical_specialty Gonadotropin-releasing hormone Biology Cerebral Ventricles Gonadotropin-Releasing Hormone Thyrotropic cell Internal medicine medicine Humans Thyrotropin-Releasing Hormone Circumventricular organs Aged Multidisciplinary Lamina terminalis Brain Middle Aged Neurosecretory Systems Preoptic area Endocrinology medicine.anatomical_structure Hypothalamus Pituitary Gland Female Neurohormones Free nerve ending hormones hormone substitutes and hormone antagonists |
| Zdroj: | Nature. 268(5619) |
| ISSN: | 0028-0836 |
| Popis: | GONADOTROPIN-releasing hormone (GnRH) and thyrotropin-releasing hormone (TRH) are two hypothalamic oligopeptides which regulate the secretion of gonadotropins and thyrotropin, respectively, from the anterior pituitary1,2. It is generally accepted that these neurohormones are produced by nerve cells, transmitted along axons and stored in nerve endings. When released, they are transferred by way of the hypothalamo–hypophyseal portal system to the anterior pituitary3. We have recently reported4 that in the human hypothalamus most of the GnRH is found in the preoptic area while TRH is localised mainly in the posterior nucleus. Exceedingly high concentrations of the two neurohormones were found in the pituitary stalk. The localisation of the two neurohormones in distinctive regions of the hypothalamus and pituitary stalk may represent sites of synthesis in neuronal cell bodies and storage in nerve terminals, respectively. It has recently been found5 that significant amounts of GnRH are present in the circumventricular organs (CVO) of the rat brain. These organs consist of specialised ependymal cells, small nerve cells and axon terminals containing small dense core vesicles. The axon terminals end on fenestrated capillaries comprising many capillary loops6. Such an anatomical arrangement is characteristic of neurohumoral secretion, and is present also in the human pituitary stalk7. In this study we have determined, by radioimmunoassay, the distribution of GnRH and of TRH in the circumventricular organs of the human brain. We report that exceedingly high concentrations of GnRH, but not of TRH, are present in one of the circumventricular organs, the organum vasculosum of the lamina terminalis (OVLT), and discuss the possible physiological function of this structure in the neural control of reproduction. |
| Databáze: | OpenAIRE |
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