Galanin jelentősége a vízanyagcsere szabályozásában, a neurohipofízis hormonok szintézisében és kiválasztásában in vivo és in vitro körülmények között patkányban = Significance of galanin in the regulation of the water metabolism; the neurohiphophyseal hormone synthesys and secretion in rat (in vivo and in vitro study)

Galanin (GAL) hatasat vizsgaltuk a vizanyagcserere es a neurohipofizis (NH) hormonok kivalasztasara, ill. a GAL-monoaminerg interakciot tanulmanyoztuk in vivo es in vitro korulmenyek kozott. Az in vivo kiserletek soran megallapitottuk, hogy intravenas (i.v.), ill. intracerebroventrikularis (i.c.v.) modon adagolt GAL a plazma vazopresszin (VP) es oxytocin (OT) bazalis szintjet nem valtoztatta meg, viszont i.c.v. GAL kezeles kivedte az ozmotikus inger es hisztamin adagolas hatasara fellepő VP szint emelkedest, mersekelte a szoptatas alatt eszlelt OT szint fokozodast. Patkany, sertes es human GAL effektusa kozt nem talaltunk elterest. Megallapitottuk, hogy a human GAL 1-16 N-terminalis fragmens kepezi a biologiailag aktiv centrumot, a C-terminalis 16-30 fragmens hatastalan. In vitro kiserleteink alkalmaval megfigyeltuk, hogy izolalt patkany NH szovetkultura szupernatans mediumahoz adott GAL dozistol fuggően csokkentette a VP es OT koncentraciot, mig a monoaminerg vegyuletek, mint dopamin, szerotonin, adrenalin, ill. noradrenalin fokozta a VP es OT szekreciot. A mediumhoz előzetesen adott GAL reszben, vagy teljes mertekben kivedte a monoamineg kezeles altal kivaltott VP es OT szint emelkedest. Eredmenyeink arra utalnak, hogy a GAL-rendszer direkt modon kepes befolyasolni a VP es OT kivalasztast. A VP esOT szekrecio GAL-erg kontrollja es a GAL-monoaminerg interakcio az izolalt NH szovetkulturaban a hipotalamusztol fuggetlenul, a hipofizis hatsolebeny szintjen is ervenyesul. | The effects of galanin (GAL) on the water metabolism and neurohypophyseal (NH) hormone secretion, and the GAL-monoaminergic interaction were examined by in vivo and in vitro methods. The in vivo experiments revealed that there were no changes in basal vasopressin (VP) secretion after GAL administration, but i.c.v. GAL treatment prevented the VP level enhancement induced by 2.5% NaCl or histamine administration, and reduced the increased plasma oxytocin (OT) level during suckling. There was no significant difference in the inhibitory effects of rat, porcine or human GAL. The human GAL 1-16 N terminal fragment was biologically active, but the 16-30 C terminal fragment was inactive. In vitro techniques demonstrated a significantly decreased VP content in NH tissue culture media following GAL administration. The monoaminergic compounds, dopamine, histamine, serotonin, adrenaline and noradrenaline uniformly increased VP or OT secretion into the supernatant media. These NH hormone level elevations were partially or totally blocked by GAL administration before monoaminergic treatment. The results indicate that NH hormone release is influenced directly by the GAL-ergic system. The GAL-ergic control and GAL-monoaminergic interaction relating to VP and OT secretion from the NH tissue in rats can occur independently of the hypothalamus, at the level of the posterior pituitary.