Korthuis R J, Grisham M B, Zimmerman B J, Granger D N, Taylor A E
Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri-Columbia 65211.
Am J Physiol. 1988 Apr;254(4 Pt 2):H702-8. doi: 10.1152/ajpheart.1988.254.4.H702.
The aim of this study was to determine whether ATP-MgCl2 or isoproterenol pretreatment would attenuate the increase in canine gracilis muscle vascular resistance and permeability associated with 4 h of occlusive ischemia followed by 1 h of reperfusion. To this end, the osmotic reflection coefficient for total plasma proteins (omega), isogravimetric capillary pressure (Pci), precapillary resistance (Ra), postcapillary resistance (Rv), and total vascular resistance (Rt) were determined for the following conditions: control, ischemia, and ischemia plus pretreatment with ATP-MgCl2 or isoproterenol. Reperfusion, after ischemia, significantly reduced omega from 0.94 +/- 0.02 to 0.64 +/- 0.02, whereas Pci was decreased by 50 +/- 4%, indicating a dramatic increase in vascular permeability. Ischemia-reperfusion was also associated with an increase in Rt of 230 +/- 22%. Similar results were obtained in muscles pretreated with isoproterenol. However, in muscles pretreated with ATP-MgCl2, omega averaged 0.98 +/- 0.09, Pci was reduced by only 15 +/- 8%, and Rt was increased by just 25 +/- 12%. The effect of ATP-MgCl2 on neutrophilic oxidative metabolism was evaluated by measuring superoxide production by activated neutrophils in the presence and absence of ATP-MgCl2. Superoxide production by activated neutrophils was significantly attenuated by ATP-MgCl2. The results of these studies indicate that pretreatment with ATP-MgCl2, but not isoproterenol, is remarkably effective in attenuating the increase in skeletal muscle vascular resistance and permeability induced by ischemia-reperfusion. The protective effect of ATP-MgCl2 may be related in part to its ability to inhibit neutrophilic superoxide production.
本研究的目的是确定ATP-MgCl₂或异丙肾上腺素预处理是否会减轻犬股薄肌血管阻力和通透性的增加，这种增加与4小时的闭塞性缺血继以1小时的再灌注有关。为此，在以下条件下测定了总血浆蛋白的渗透反射系数（ω）、等重量毛细血管压力（Pci）、毛细血管前阻力（Ra）、毛细血管后阻力（Rv）和总血管阻力（Rt）：对照、缺血、以及缺血加ATP-MgCl₂或异丙肾上腺素预处理。缺血后的再灌注显著降低了ω，从0.94±0.02降至0.64±0.02，而Pci降低了50±4%，表明血管通透性显著增加。缺血-再灌注还与Rt增加230±22%有关。在用异丙肾上腺素预处理的肌肉中也得到了类似的结果。然而，在用ATP-MgCl₂预处理的肌肉中，ω平均为0.98±0.09，Pci仅降低15±8%，Rt仅增加25±12%。通过在有和没有ATP-MgCl₂的情况下测量活化中性粒细胞产生的超氧化物来评估ATP-MgCl₂对中性粒细胞氧化代谢的影响。ATP-MgCl₂显著减弱了活化中性粒细胞产生的超氧化物。这些研究结果表明，ATP-MgCl₂预处理而非异丙肾上腺素预处理在减轻缺血-再灌注诱导的骨骼肌血管阻力和通透性增加方面非常有效。ATP-MgCl₂的保护作用可能部分与其抑制中性粒细胞超氧化物产生的能力有关。
