Mazzoni M C, Skalak T C, Schmid-Schönbein G W
Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla 92093.
Am J Physiol. 1990 Dec;259(6 Pt 2):H1860-8. doi: 10.1152/ajpheart.1990.259.6.H1860.
Because lymphatics in skeletal muscle have no smooth muscle, they are expanded and compressed solely by stresses in the surrounding tissue. Whole organ experiments have indicated that lymph flow is significantly elevated during muscle activity, yet the underlying mechanism for lymph formation has not been identified. To investigate this mechanism, specimens of the rat spinotrapezius muscle were fixed in situ at the undeformed in vivo length, and also in the stretched and contracted states, for histological examination. Cross-sectional areas of lymphatic vessels, skeletal muscle fibers, blood vessels, and interstitial space were measured using a stereological technique. The in situ preparation with intact muscle fascia was essential for preservation of interstitial volume. The lymphatic cross-sectional areas and muscle stretch ratios from 20 rats showed that lymphatic volume increased by 57% for a 20% stretch, and decreased by 45% for a 20% contraction. Deformation of the incompressible muscle fibers appears to inversely affect surrounding tissue structures; e.g., decreased fiber cross-sectional area during stretch increases interstitial spacing between fibers, which in turn expands lymphatics.
由于骨骼肌中的淋巴管没有平滑肌，它们仅通过周围组织的压力而扩张和压缩。全器官实验表明，肌肉活动期间淋巴流量显著升高，但淋巴形成的潜在机制尚未明确。为了研究这一机制，将大鼠斜方肌标本在体内未变形的长度下原位固定，同时也在拉伸和收缩状态下固定，用于组织学检查。使用体视学技术测量淋巴管、骨骼肌纤维、血管和间质空间的横截面积。带有完整肌肉筋膜的原位标本对于保留间质体积至关重要。来自20只大鼠的淋巴管横截面积和肌肉拉伸率表明，拉伸20%时淋巴体积增加57%，收缩20%时淋巴体积减少45%。不可压缩的肌肉纤维的变形似乎会对周围组织结构产生相反的影响；例如，拉伸过程中纤维横截面积减小会增加纤维之间的间质间距，进而使淋巴管扩张。
