年龄对大鼠孤束核注射神经肽Y后心血管反应无影响。

Lack of effect of age on the cardiovascular response to neuropeptide Y injection in the rat nucleus tractus solitarius.

Morris M J, Pavia J M

School of Biological and Chemical Sciences, Deakin University, Geelong, Victoria, Australia.

Clin Exp Pharmacol Physiol. 1997 Feb;24(2):162-5. doi: 10.1111/j.1440-1681.1997.tb01801.x.

Abstract

Neuropeptide Y (NPY) is colocalized with catecholamines in central regions involved in blood pressure regulation and exerts depressor responses in the nucleus tractus solitarius (NTS). Ageing is accompanied by a decline in baroreflex function and a reduction in NPY concentrations in some brain areas. The present study investigated whether the cardiovascular response to NPY microinjection into the NTS and medullary NPY concentrations were conserved in aged rats. 2. Neuropeptide Y (6 pmol in 100 nL) unilaterally injected into the NTS of anaesthetized 3- or 17-month-old male Sprague-Dawley rats produced a prompt 9-10% fall in mean arterial pressure (MAP), which tended to last longer in aged rats. Decreases in heart rate (HR) observed following NPY administration into the NTS were modest but more prolonged than the depressor responses. ANOVA with repeated measures demonstrated no significant effect of age on the MAP or HR response to NPY injection into the NTS. Neuropeptide Y concentrations in the dorsomedial and ventrolateral medulla were not different between the two age groups. 3. Thus, the depressor and bradycardic responses to exogenous NPY administration in the NTS were maintained with age, in keeping with the observation of similar medullary NPY concentrations in adult and aged rats.

摘要

神经肽Y（NPY）与儿茶酚胺在参与血压调节的中枢区域共定位，并在孤束核（NTS）中发挥降压反应。衰老伴随着压力反射功能的下降以及某些脑区NPY浓度的降低。本研究调查了老龄大鼠对向NTS微量注射NPY的心血管反应以及延髓NPY浓度是否保持不变。2. 向麻醉的3月龄或17月龄雄性Sprague-Dawley大鼠的NTS单侧注射神经肽Y（100 nL中含6 pmol），可使平均动脉压（MAP）迅速下降9-10%，老龄大鼠的这种下降趋势持续时间更长。向NTS注射NPY后观察到的心率（HR）下降幅度较小，但比降压反应持续时间更长。重复测量方差分析表明，年龄对向NTS注射NPY后的MAP或HR反应无显著影响。两个年龄组的背内侧和腹外侧延髓中的神经肽Y浓度没有差异。3. 因此，随着年龄增长，NTS对外源性NPY给药的降压和心动过缓反应得以维持，这与成年大鼠和老龄大鼠延髓中NPY浓度相似的观察结果一致。