Björnberg J, Maspers M, Mellander S
Department of Physiology and Biophysics, University of Lund, Sweden.
Acta Physiol Scand. 1989 Feb;135(2):83-94. doi: 10.1111/j.1748-1716.1989.tb08555.x.
The metabolic control of the vascular bed in cat gastrocnemius muscle during exercise was studied with a new technique (Björnberg et al. 1988) permitting continuous and simultaneous recordings of arteriolar and capillary pressures, and of resistances in the following consecutive vascular section: proximal arterial resistance vessels greater than 25 microns, arterioles less than 25 microns, and on the venous side. The study thereby provided quantitative data for resistance and active intrinsic tone in these vascular segments at rest, during graded exercise vasodilatation, and in the post-exercise period. Slight activation of the metabolic control system by low-frequency somatomotor nerve stimulation ('light exercise') caused inhibition of intrinsic tone and decreased vascular resistance selectively in the arteriolar section. At increasing workloads, arteriolar resistance was further decreased, but resistance and tone in the proximal arterial resistance vessels and the veins then became clearly reduced as well. This difference in effectiveness of the metabolic control system on the different segments of the vascular bed was expressed quantitatively in terms of a 'metabolic vasodilator index'. Graded activation of the metabolic control system led to a marked segmental redistribution of intrinsic vascular tone, in turn resulting in an increased pressure drop across the proximal arterial vessels in the veins and a decreased pressure drop over the arterioles. The observed decrease in the pre- to post-capillary resistance ratio caused, at a constant arterial pressure of 100 mmHg, a graded increase in capillary pressure with increasing workloads, at maximum vasodilatation by an average value of 14 mmHg above the resting control value of 15.4 +/- 0.6 mmHg. In the post-exercise period, recovery of vascular tone to control was more rapid in the proximal arterial resistance vessels and the veins than in the arteriolar segment.
采用一项新技术（比约恩贝里等人，1988年）对猫腓肠肌血管床在运动期间的代谢控制进行了研究，该技术可连续同时记录小动脉和毛细血管压力，以及以下连续血管段的阻力：直径大于25微米的近端动脉阻力血管、直径小于25微米的小动脉以及静脉侧。该研究从而提供了这些血管段在静息状态、分级运动血管舒张期间以及运动后阶段的阻力和主动内在张力的定量数据。通过低频躯体运动神经刺激（“轻度运动”）对代谢控制系统进行轻微激活，可抑制内在张力，并选择性地降低小动脉段的血管阻力。随着工作量增加，小动脉阻力进一步降低，但近端动脉阻力血管和静脉的阻力及张力随后也明显降低。代谢控制系统对血管床不同段的有效性差异通过“代谢性血管舒张指数”进行了定量表达。代谢控制系统的分级激活导致内在血管张力出现明显的节段性重新分布，进而导致静脉中近端动脉血管两端的压力降增加，小动脉上的压力降减小。在动脉压恒定为100 mmHg的情况下，观察到的毛细血管前与毛细血管后阻力比值降低，随着工作量增加导致毛细血管压力分级增加，在最大血管舒张时，平均比静息对照值15.4±0.6 mmHg高出14 mmHg。在运动后阶段，近端动脉阻力血管和静脉的血管张力恢复到对照水平的速度比小动脉段更快。
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