Układ prolaktynergiczny? Wytwarzanie i rola prolaktyny w mózgu

Abstrakt

Summary Prolactin is a polypeptide hormone that undergoes many posttranslational modifications which modulate its biological functions. Functions of prolactin can be also modulated by different forms of the prolactin receptor. Although the main source of the hormone is the anterior pituitary gland, it is produced in many tissues, e.g. in the immune system and brain. Both the hormone and its mRNA were detected in many regions of the rat brain but prolactin-immunoreactive neuronal cell bodies were observed only in the hypothalamus. Prolactin receptors were also detected in many brain regions but, surprisingly, were not as widely distributed as prolactin. Brain regions differ in proportions of prolactin receptor forms. These observations may explain why prolactin play many functions in the brain (e.g. neuromodulation, regulation of neurotransmitter release). As prolactin and prolactin receptor knockout mice do not develop any serious defects in the brain functioning, it is hypothesized that prolactin regulation is subtle and also may be partially compensated by growth hormone and placental lactogen.