Lasbennes F, Lacombe P, Seylaz J
Laboratoire de Physiologie et Physiopathologie Cérébrovasculaire, I.N.S.E.R.M., U. 182, C.N.R.S., U.A. 641, Université Paris VII, France.
Brain Res. 1988 Jun 28;454(1-2):205-11. doi: 10.1016/0006-8993(88)90819-0.
The effect of an acute i.v. infusion of noradrenaline (NA) on regional cerebral blood flow (rCBF) was investigated in the awake rat using [14C]iodoantipyrine as diffusible tracer. The contribution of vascular monoamine oxidase (MAO) to the efficiency of the enzymatic blood-brain barrier (BBB) to catecholamines was assessed by measuring the multiregional cerebrovascular response to circulating NA given alone or after i.v. administration of the monoamine oxidase inhibitor, clorgyline. Since i.v. infusion of NA elevates blood pressure, the influence of NA on the cerebrovascular bed was first studied by determining the relationship between rCBF and the mean arterial pressure (MAP). When the MAP was only slightly increased (to approximately 130 mm Hg), a trend to flow decrease under NA infusion was observed. Secondly, we compared the effects of NA on rCBF in animals treated or not treated with clorgyline. This was performed under moderate hypertension (within the 'autoregulated' range of MAP) to avoid any risk of mechanical damage to the BBB. Clorgyline administration alone did not significantly modify rCBF, but the subsequent i.v. infusion of NA induced an increase in rCBF (weighted mean 14%) in all structures investigated. The differences being statistically significant (P less than 0.05) in 5 out of 13 structures by up to 20%. Compared to studies involving disruption of the morphological BBB in which plasma NA elicits a widespread important increase in blood flow, the weak cerebrovascular effects we observed provide indirect evidence for the efficiency of the BBB to catecholamines in the conscious rat within the autoregulated range of arterial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
使用[14C]碘安替比林作为可扩散示踪剂，在清醒大鼠中研究了静脉内急性输注去甲肾上腺素（NA）对局部脑血流量（rCBF）的影响。通过测量单独给予循环NA或静脉内给予单胺氧化酶抑制剂氯吉兰后多区域脑血管反应，评估血管单胺氧化酶（MAO）对酶性血脑屏障（BBB）对儿茶酚胺的效率的贡献。由于静脉内输注NA会升高血压，因此首先通过确定rCBF与平均动脉压（MAP）之间的关系来研究NA对脑血管床的影响。当MAP仅略有升高（至约130 mmHg）时，观察到在NA输注下血流量有下降趋势。其次，我们比较了氯吉兰治疗或未治疗的动物中NA对rCBF的影响。这是在中度高血压（在MAP的“自动调节”范围内）下进行的，以避免对BBB造成机械损伤的任何风险。单独给予氯吉兰不会显著改变rCBF，但随后静脉内输注NA会导致所有研究结构中的rCBF增加（加权平均值为14%）。在13个结构中的5个结构中，差异具有统计学意义（P小于0.05），增幅高达20%。与涉及破坏形态学BBB的研究相比，在该研究中血浆NA会引起广泛的重要血流增加，我们观察到的微弱脑血管效应为清醒大鼠在动脉压自动调节范围内BBB对儿茶酚胺的效率提供了间接证据。（摘要截断于250字）
