抄録
Neurohypophyseal homones, vasopressin and oxytocin, are known to be involved in body fluid homeostasis as anti-diuretic hormone, milk-ejection reflex and maternal behavior. The gene targeting techniques have already generated knockout mice of vasopressin receptors and oxytocin receptor. Recently, we have generated vasopressin-green fluorescent protein (GFP) transgenic and oxytocin-cyan fluorescent protein (CFP) transgenic rats to visualize vasopressin- and oxytocin-secreting neurons in the hypothalamus and their terminals in the posterior pituitary. In vasopressin-GFP transgenic rats GFP fluorescence was observed in the magnocellular division of the paraventricular nucleus (PVN), the supraoptic nucleus (SON), the suprachiasmatic nucleus and axon terminals in the posterior pituitary. In the magnocellular division of the PVN and SON GFP fluorescence was marked increased after dehydration and chronic salt loading. Acute and chronic stresses caused a significant increase of GFP fluorescence in the parvocellular division of the PVN. In oxytocin-CFP transgenic rats CFP fluorescence was also observed in the magnocellular division of the PVN, SON and axon terminals in the posterior pituitary. Strong CFP fluorescence in the PVN and SON were observed in lactating transgenic rats. These rats give us unique new tool to study vasopressin- and oxytocin-secreting neurons in in vivo experiments, using electrophysiology and monitering system of these fluorescences. [J Physiol Sci. 2008;58 Suppl:S20]
