慢性缺氧大鼠膈肌毛细血管密度变化

Changes of capillary density of rat diaphragm after exposure to chronic hypoxia

目的：测定慢性缺氧大鼠膈肌毛细血管密度变化。方法：用肌球蛋白ＡＴＰ（ｍＡＴＰ）酶组化进行肌纤维分类和显示毛细血管，并通过计算机图象分析系统。结果：慢性缺氧大鼠膈肌毛细血管密度显著增加，主要表现为单位面积内毛细血管数量增加和每根毛细血管供应的肌纤维横截面积缩小。结论：膈肌毛细血管密度增加可能是肌纤维横截面积缩小和毛细血管新生的结果。

AIM and METHODS: (the deep part of tibilias anterior and solues) after exposure to nomobaric hypoxia (10% O 2) or simulated hypobaric (5000m.a.s.l.)for one or three months were observed. The muscle fiber types and capillaries were identified by myosin ATPase histochemistry,and the CD were measured by using a computerised image-processing system.In the four muscles observed,the capillaries per mm 2(Nc/mm 2) were significantly increased and the cross sectional area of muscle fiber provided for a capillary (CSAf/C) were significantly decreased.Significant increase in the capillary or fiber ratio(capillaries per mm 2 divided by fibers per mm 2,Nc/Nf)and in the number of adjacent capillaries per fiber (Nc/f) were only observed in DIcos and/or DIcru after exposure to hypoxia for three months.CONCLUSION: the decreased CSAf,the neoformed capillaries may be partially attributable to the increased capillary density in DIcos.