2002, Number 6
Rev Fac Med UNAM 2002; 45 (6)
Physiology of reproduction: hormones and gonadotrophins
Prieto GB,Velázquez PM
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Reproduction in almost all animal species is regulated by a neuro-hormonal mechanism in both sexes that must be synchronized, through chemical changes in various parts, which begins to manifest with in the courting ritual. The follicular stimulating and lutein hormones from the pituitary gland produce the maturation of the gonads and steroid genesis. However, other hormones from the hypothalamus allow the pituitary gland to liberate gonadotrophins, GnRH which is a decapeptide that has been preserved from fish to humans. The regulating gene is located in chromosome 8. At first glance, this hormone appears to be generated by pulses that the steroids unlock in the hypothalamus. However, since is secreted in small quantity and has a short half-life, there have been suggestions that a local synthesis of the same hormone takes place in the receptor. Regulation of the reproduction system is controlled by a very complex mechanism. Further elements intervene in the system such as the GABA, endorphins dopamine, nora renaline and serotonin, as well as local non-steroidal elements such as inhibine and activine. As a spin-off, advances in the knowledge of this area have shown a clinical usefullness, illustrated by GnRH analogs which are used in the treatment of early puberty, ovarian cysts and endometriosis.
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