The role of the hypothalamus-hypophysis-adrenal gland axis in the regulation of reproduction

The hypothalamus-hypophysis-adrenal axis is the key regulator of secretion of adrenal hormones. Its role in reaction to stress is widely known but nowadays more attention is paid to its influence on reproduction. Corticotropin-releasing factor (CRF) is the main neuroregulator of the hypothalamus-hypophysis-adrenal axis in mammals. Moreover, it regulates the functioning of the reproductive system both during pregnancy and at other times. CRF also participates in regulation of the initiation of labour. The structure of CRF has high homology to the peptides urotensin I, sauvagine and urocortin. In 1996 human urocortin was identified. The presence of urocortin has been revealed in the central nervous system, reproductive system and endocrine system. This suggests that urocortin has an important physiological role in the hypothalamus-hypophysis-ovaries system. It is known that both urocortin and CRF can bind CRF receptor type 1 (CRFR1) and stimulate the secretion of adrenocorticotropic hormone (ACTH) in the cells of the anterior lobe of the hypophysis. There is progress in the knowledge of the localisation and role of urocortin in reproduction. The paper is a review of the present knowledge of the action of the role of CRF in the control of the reproductive system. The most recent investigations concerning the importance of urocortin for the function of the ovaries, the uterus and the placenta are also discussed. Endocrinology is considered to be a developing field of science. It is believed that exploration of the action of hormones and peptides improves the diagnosis, prevention and treatment of diseases connected with their functions.