Basic researches on the high altitude training : mechanism of vascular and pulmonary systems

在低碳酸性低氧暴露（10%O2在N2中8周）后，检查三种类型的失神经大鼠颈动脉体的形态学变化。去窦神经和交感神经大鼠（SD+S）颈动脉体明显增大，血管扩张。而单纯去窦神经（SD）和去窦神经+交感神经+迷走神经（SD+S+V）大鼠颈动脉体无明显变化。这些结果表明，在大鼠的交感神经和迷走神经的大鼠或这两个神经完整的大鼠（SD大鼠）的颈动脉体不会有形态学变化。本文观察了自发性高血压大鼠（SHR）、年龄匹配的正常血压Wistar大鼠（NWR）和年龄匹配的遗传相似的Wistar大鼠（WKY）颈动脉体的形态学特征。SHR的颈动脉体大于NWR和WKY。SHR颈动脉体VIP纤维密度低于WKY，而SP、CGRP、NPY纤维密度与NWR、WKY相似。提示高血压大鼠颈动脉体增大的机制与缺氧大鼠不同。

Morphological changes in the carotid bodies of three types of denervated rats were examined after hypocapnic hypoxic exposure (10% 02 in N2 for 8 weeks). The carotid bodies of rats denervated of both sinus and sympathetic nerves (SD+S) were significantly enlarged with vascular expansion. But there were no significant changes in the carotid bodies of rats denervated of the sinus nerve alone (SD) or rats denervated of the sinus, sympathetic, and vagal nerves (SD+S+V). These findings indicate that there would be no morphological changes in the carotid bodies of rats denervated of the sympathetic and vagal nerves rats or rats with these two nerves intact (SD rats). This suggests that the enlargement of the carotid body in hypoxic conditions may depend on well-balanced sympathetic and para-sympathetic control.Morphological characteristics in the carotid bodies of spontaneously hypertensive rats (SHR) and those of age-matched normotensive Wistar rats (NWR) as well as age-matched genetically comparable Wistar rats (WKY) were examined. The carotid bodies of SHR were greater than those of NWR and WKY. The density of VIP varicose fibers in the carotid bodies of SHR were smaller than that in the carotid bodies of WKY, although that of SP, CGRP, and NPY fibers was similar to that in the carotid bodies of NWR and WKY. These findings suggest that the mechanisms of carotid body enlargement in hypertensive rats are different from those in hypoxic rats.