Gray S D
Department of Human Physiology, School of Medicine, University of California, Davis 95616.
Microvasc Res. 1988 Nov;36(3):228-38. doi: 10.1016/0026-2862(88)90024-6.
Various studies have suggested that hypertension causes a closure and eventual loss of microvessels. In muscle tissue that purported pattern of vascular rarification has been associated with a simultaneous loss of slow twitch fibers. The present study uses histochemical techniques to examine both the capillarization and distribution of fast (FOG) and slow (SO) twitch oxidative fibers, the most vascularized of the fiber types, in five muscles of spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats: adductor magnus (AM), biceps femoris (BF), spinotrapezius (SP), medial gastrocnemius (MG), and soleus (SOL). The results show that FOG and SO tend to be slightly smaller in cross-sectional area in SHR, but that the percentage of those fibers in the total population is not decreased in any of the SHR muscles examined. Capillary/fiber (C/F) ratios for most fiber categories were not significantly different in the two strains but tended toward slightly higher values in SHR. Since capillary density (C/mm2) is related to both fiber size and C/F ratio, density values tended to be higher, rather than lower, in SHR. The data indicate that there is neither an anatomical rarification of capillaries, nor a loss of FOG or SO fibers in spontaneous hypertension.
多项研究表明，高血压会导致微血管闭塞并最终消失。在肌肉组织中，这种所谓的血管稀疏模式与慢肌纤维的同时丧失有关。本研究采用组织化学技术，检查自发性高血压（SHR）大鼠和血压正常的Wistar-Kyoto（WKY）大鼠的五块肌肉中快速（FOG）和慢速（SO）抽搐氧化纤维的毛细血管化和分布情况，这两种纤维类型是血管化程度最高的：大收肌（AM）、股二头肌（BF）、斜方肌（SP）、腓肠肌内侧头（MG）和比目鱼肌（SOL）。结果表明，SHR中FOG和SO的横截面积往往略小，但在所检查的任何SHR肌肉中，这些纤维在总纤维中的百分比并未降低。两种品系中大多数纤维类别的毛细血管/纤维（C/F）比率无显著差异，但SHR中的该比率往往略高。由于毛细血管密度（C/mm2）与纤维大小和C/F比率均相关，因此SHR中的密度值往往较高，而非较低。数据表明，自发性高血压既不存在毛细血管的解剖学稀疏，也不存在FOG或SO纤维的丧失。
