Gmitrov Juraj, Ohkubo Chiyoji, Okano Hideyuki
Department of Physiological Hygiene, The National Institute of Public Health, Tokyo, Japan.
Bioelectromagnetics. 2002 Apr;23(3):224-9. doi: 10.1002/bem.10007.
We showed previously in rabbits that 0.2 and 0.35 T static magnetic field (SMF) modulated systemic hemodynamics by arterial baroreceptors. We now have measured the effect of 0.25 T SMF on microcirculation within cutaneous tissue of the rabbit ear lobe by the rabbit ear chamber (REC) method. Forty experimental runs (20 controls and 20 SMF) were carried out in eight different rabbits with an equal number of control and SMF experiments on each individual. Rabbits were sedated by pentobarbital sodium (5 mg/kg/h, i.v.) during the entire 80 min experiment. SMF was generated by four neodium-iron-boron alloy (Nd2-Fe14-B) magnets (15 x 25 x 30 mm, Neomax, PIP - Tokyo Co., Ltd., Tokyo, Japan), positioned around the REC on the observing stage of an optical microscope. The direct intravital microscopic observation of the rabbit's ear microvascular net, along with simultaneous blood flow measurement by microphotoelectric plethysmography (MPPG), were performed PRE (20 min, baseline), DURING (40 min), and POST (20 min) magnetic field exposure. The control experiments were performed under the same conditions and according to the same time course, but without magnetic field. Data were analyzed comparing MPPG values and percent change from baseline in the same series, and between corresponding sections of control and SMF runs. In contrast to control series (100+/-0.0%-90.0+/-5.4%-87.7+/-7.1%, PRE-EXPOSURE-POST), after magnetic field exposure we observed increased blood flow (100+/-0.0%-117.8+/-9.6%*-113.8+/-14.0%, *P<0.05) which gradually decreased after exposure cessation. We propose that long exposure of a high level nonuniform SMF probably modifies microcirculatory homeostasis through modulation of the local release of endothelial neurohumoral and paracrine factors that act directly on the smooth muscle of the vascular wall, presumably by affecting ion channels or second messenger systems.
我们之前在兔子身上发现，0.2和0.35特斯拉的静磁场（SMF）通过动脉压力感受器调节全身血流动力学。我们现在采用兔耳腔（REC）方法，测量了0.25特斯拉SMF对兔耳叶皮肤组织内微循环的影响。在8只不同的兔子身上进行了40次实验（20次对照和20次SMF），每只兔子的对照和SMF实验数量相等。在整个80分钟的实验过程中，兔子通过静脉注射戊巴比妥钠（5毫克/千克/小时）进行麻醉。SMF由四个钕铁硼合金（Nd2-Fe14-B）磁体（15×25×30毫米，Neomax，PIP - 东京有限公司，东京，日本）产生，放置在光学显微镜观察台上REC周围。在磁场暴露前（20分钟，基线）、期间（40分钟）和之后（20分钟），对兔耳微血管网进行直接活体显微镜观察，并同时通过微光电容积描记法（MPPG）测量血流。对照实验在相同条件下并按照相同的时间进程进行，但不施加磁场。分析数据时，比较了同一系列中MPPG值和相对于基线的百分比变化，以及对照和SMF实验相应部分之间的差异。与对照系列（100±0.0%-90.0±5.4%-87.7±7.1%，暴露前-暴露中-暴露后）相比，磁场暴露后我们观察到血流增加（100±0.0%-117.8±9.6%*-113.8±14.0%，*P<0.05），暴露停止后血流逐渐下降。我们认为，长时间暴露于高强度非均匀SMF可能通过调节内皮神经体液和旁分泌因子的局部释放来改变微循环稳态，这些因子可能通过影响离子通道或第二信使系统直接作用于血管壁平滑肌。
