Sato K, Crofton J T, Wang Y X, Share L
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163, USA.
Brain Res. 1995 Aug 14;689(1):71-8. doi: 10.1016/0006-8993(95)00454-x.
Neuropeptide Y (NPY) and norepinephrine are co-localized in the noradrenergic projection from the A1 nucleus of the medulla to the vasopressinergic magnocellular neurons of the supraoptic and paraventricular nuclei. Because this pathway is involved in the control of vasopressin release, we have examined the possibility that NPY and norepinephrine interact in this control. Because the stimulation of vasopressin release by the intracerebroventricular (i.c.v.) administration of norepinephrine is greater in male than in female rats, the experiments were carried out in conscious male rats and in female rats in the proestrous and non-proestrous phases of the estrous cycle. NPY (940 pmol i.c.v.) caused small sustained increases in plasma vasopressin concentrations that were greater in proestrous than in non-proestrous females and males. Norepinephrine i.c.v. increased plasma vasopressin levels transiently and to a greater extent in females than males. When NPY and norepinephrine were given together, the pattern of the vasopressin response was similar to that of norepinephrine alone. The magnitude of this response in males and proestrous females did not differ from that to norepinephrine alone; in non-proestrous females the response was twice that to norepinephrine alone. In non-proestrous rats, NPY also enhanced the pressor response to norepinephrine. Thus, NPY interacts centrally with norepinephrine in vasopressin release and cardiovascular function and this effect is dependent upon gender and phase of the estrous cycle.
神经肽Y（NPY）和去甲肾上腺素共同存在于从延髓A1核投射至视上核和室旁核中分泌血管加压素的大细胞神经元的去甲肾上腺素能投射通路中。由于该通路参与血管加压素释放的调控，我们研究了NPY和去甲肾上腺素在这一调控过程中相互作用的可能性。因为脑室内（i.c.v.）注射去甲肾上腺素对雄性大鼠血管加压素释放的刺激作用大于雌性大鼠，所以实验在清醒的雄性大鼠以及处于动情周期动情前期和非动情前期的雌性大鼠中进行。脑室内注射NPY（940 pmol）使血浆血管加压素浓度出现小幅持续升高，动情前期雌性和雄性大鼠的升高幅度大于非动情前期。脑室内注射去甲肾上腺素可使血浆血管加压素水平短暂升高，且雌性大鼠的升高幅度大于雄性大鼠。当NPY和去甲肾上腺素同时注射时，血管加压素的反应模式与单独注射去甲肾上腺素时相似。雄性大鼠和动情前期雌性大鼠的这种反应幅度与单独注射去甲肾上腺素时无差异；非动情前期雌性大鼠的反应幅度是单独注射去甲肾上腺素时的两倍。在非动情前期大鼠中，NPY还增强了对去甲肾上腺素的升压反应。因此，NPY在血管加压素释放和心血管功能方面与去甲肾上腺素在中枢存在相互作用，且这种作用取决于性别和动情周期阶段。
