An investigation of arterial insufficiency in rat hindlimb. A combined 31P-n.m.r. and bloodflow study.
An investigation of arterial insufficiency in rat hindlimb. A combined 31P-n.m.r. and bloodflow study.
复制标题
大鼠后肢动脉供血不足的研究。
作者：
R. Challiss;D. J. Hayes;R. Petty;G. Radda
本文建立了单侧股动脉结扎和切开的小动物模型。在结扎后12小时、4天、7天和14天，用31P-n.m.r观察受影响肌肉的代谢和灌注变化。静息和1hz等距肌肉收缩时的微球输注。静息时，磷酸肌酸浓度与结扎后4天的平均对照值（36.0 +/- 1.0 mM）相似，但在结扎后12 h （28.5 +/- 3.6 mM）显著降低。结扎后7天，无机磷酸盐浓度显著升高。肌内ph值无显著差异。在刺激受影响的肌肉量后，观察到磷酸肌酸利用率的时间依赖性改善，结扎后14天磷酸肌酸利用率与平均对照值无显著差异。收缩引起的肌内ph值下降也有类似的改善。休息时，与未受影响的对侧肢体相比，结扎肢体肌肉的血流量没有显著差异。然而，受影响肌肉块的等长收缩导致结扎后12小时充血反应明显降低。此后，观察到刺激期间组织灌注的时间依赖性改善，这与磷酸肌酸利用和肌肉内pH变化的改善相一致。讨论了氧输送、高能磷酸盐利用和力维持之间的相互关系。
A small animal model of arterial insufficiency is presented which involves unilateral femoral artery ligation and section. Invoked alterations in metabolism and perfusion of the affected muscle mass have been investigated 12 h, 4, 7 and 14 days post-ligation by 31P-n.m.r. and microsphere infusion, both at rest and during isometric muscle contraction at 1 Hz. At rest, the concentration of phosphocreatine was similar to the mean control value (36.0 +/- 1.0 mM) from 4 days post-ligation, but was significantly lower at 12 h (28.5 +/- 3.6 mM). Inorganic phosphate concentrations were significantly elevated for 7 days post-ligation. No significant differences were noted in intramuscular pH. Upon stimulation of the affected muscle mass, a time-dependent improvement in phosphocreatine utilization was observed such that 14 days post-ligation phosphocreatine utilization was not significantly different from mean control values. A similar amelioration was noted for the contraction-induced fall in intramuscular pH. At rest, no significant differences in bloodflow to the muscles of the ligated limb compared with the unaffected contralateral limb were observed. However, isometric contraction of the affected muscle mass resulted in a markedly reduced hyperaemic response 12 h post-ligation. Thereafter, a time-dependent improvement in tissue perfusion during stimulation was observed which paralleled the improvements in phosphocreatine utilization and intramuscular pH changes. The results presented are discussed with respect to the interrelationship between oxygen delivery, high energy phosphate utilization and force maintenance.