Vasopressin release from the rat hypothalamo-neurohypophysial system: effects of gonadotrophin-releasing hormone (GnRH), its analogues and melatonin.

The influence of gonadotrophin-releasing hormone (GnRH) and its analogues (i.e., agonist and antagonist) on vasopressin (VP) release from the rat hypothalamo-neurohypophysial (H-N) system was studied both in vitro and in vivo.

Hypothalamic gonadotropin-releasing hormone receptor activation stimulates oxytocin release from the rat hypothalamo-neurohypophysial system while melatonin inhibits this process.

The present study was undertaken to investigate the influence of gonadotropin-releasing hormone (GnRH) and its agonist and antagonist on oxytocin (OT) release from the rat hypothalamo-neurohypophysial (H-N) system. An additional aim was to determine whether the possible response of oxytocinergic neurons to these peptides could be modified by melatonin through a cAMP-dependent mechanism. The results show that the highly selective GnRH agonist (i.

Oxytocin release from the rat neurohypophysis into the blood: effects of tachykinin NK-1 and NK-2 receptors agonists and antagonists.

The aim of the present study was to investigate the effect of peptide NK-1 and NK-2 receptors agonists and antagonists (and their natural ligands, i.e., substance P and neurokinin A) on the oxytocin (OT) secretion from the rat neurohypophysis into the blood.

Effect of melatonin on the vasopressin secretion as influenced by tachykinin NK-1 receptor agonist and antagonist: in vivo and in vitro studies.

The aim of the present study was to investigate the influence of melatonin on vasopressin (AVP) release from the rat hypothalamo-neurohypophysial (H-NH) system, both in vivo and in vitro, possibly modified by the peptide NK-1 and/or NK-2 receptor agonists and antagonists. Highly selective NK-1 receptor agonist, i.e.

[The influence of melatonin on human reproduction].

This paper reviews the possible participation of melatonin in the process of human reproduction. The results of several studies have shown the clear correlation between melatonin and gonadotropins and/or sexual steroids, which suggest that melatonin may be involved in the sexual maturation, ovulation or menopause. Decreased secretion of melatonin which coexists with increased fertility in the summer is specific for women living on the north hemisphere.