Fletcher E C, Lesske J, Behm R, Miller C C, Stauss H, Unger T
Department of Pharmacology, Ruprecht-Karls University, Heidelberg, Federal Republic of Germany.
J Appl Physiol (1985). 1992 May;72(5):1978-84. doi: 10.1152/jappl.1992.72.5.1978.
We have described a rat model that responds to repetitive episodic hypoxia (12-s infusions of nitrogen into daytime sleeping chambers every 30 s, 7 h/day for 35 days) with an increase in diurnal systemic blood pressure. We hypothesized that afferent information from the peripheral chemoreceptors may be necessary to produce diurnal blood pressure elevation in this hypoxia model. Carotid body denervation (CBD) was accomplished by severing both carotid sinus nerves in two groups of male Wistar rats (250-375 g). Group 4 CBD rats were subjected to intermittent hypoxia for 35 days (3-5% nadir ambient O2) as described above, whereas group 5 CBD rats remained unhandled in their usual cages. Additional sham-operated controls included group 2 sham-"hypoxia" rats, which were housed in chambers identical to the hypoxia rats but supplied with compressed air instead of nitrogen, group 1 (not denervated) rats, which remained unhandled in their usual cages, and group 3 sham-operated rats, which were subjected to 35 days of intermittent hypoxia identical to group 4 CBD rats. Femoral arterial baseline and end-of-study blood pressures were measured in conscious rats. The group 3 rats exposed to episodic hypoxia displayed a 13-mmHg increase in mean blood pressure, whereas the other groups showed no significant change from baseline. Left ventricular hypertrophy was evident in all rats exposed to episodic hypoxia, but right ventricular hypertrophy was evident only in the group 4 rats. All CBD rats developed increased hematocrit and hemoglobin, while the group 3 rats (non-CBD, episodic hypoxia) did not. The baroreceptor reflex at baseline was not depressed in the CBD rats.(ABSTRACT TRUNCATED AT 250 WORDS)
我们已经描述了一种大鼠模型，该模型对重复性间歇性缺氧（每30秒向白天睡眠室注入12秒氮气，每天7小时，持续35天）会出现昼夜系统性血压升高。我们假设，来自外周化学感受器的传入信息可能是在这种缺氧模型中产生昼夜血压升高所必需的。通过切断两组雄性Wistar大鼠（250 - 375克）的双侧颈动脉窦神经来实现颈动脉体去神经支配（CBD）。第4组CBD大鼠如上述接受间歇性缺氧35天（最低环境氧气含量为3 - 5%），而第5组CBD大鼠则留在其常规笼中未作处理。额外的假手术对照组包括第2组假“缺氧”大鼠，它们被安置在与缺氧大鼠相同的舱室中，但供应的是压缩空气而非氮气；第1组（未去神经支配）大鼠，它们留在常规笼中未作处理；以及第3组假手术大鼠，它们接受了与第4组CBD大鼠相同的35天间歇性缺氧处理。在清醒大鼠中测量股动脉基线血压和研究结束时的血压。暴露于间歇性缺氧的第3组大鼠平均血压升高了13 mmHg，而其他组与基线相比无显著变化。所有暴露于间歇性缺氧的大鼠均出现左心室肥厚，但仅第4组大鼠出现右心室肥厚。所有CBD大鼠的血细胞比容和血红蛋白均升高，而第3组大鼠（非CBD，间歇性缺氧）则未升高。CBD大鼠的基线压力感受器反射未受抑制。（摘要截短于250字）
