Charash W E, Saba T M, Lewis E P, Lewis M A
Department of Physiology, Albany Medical College, Albany, New York 12208.
Am J Physiol. 1988 Dec;255(6 Pt 2):H1421-8. doi: 10.1152/ajpheart.1988.255.6.H1421.
An increase in pulmonary transvascular protein clearance is seen in sheep following postoperative bacteremia. We evaluated whether this increased protein clearance is specific for the lung by comparing in sheep the effect of postoperative bacteremia on both pulmonary and prefemoral lymph protein clearance. Fibronectin, implicated as a factor influencing vascular permeability, was also measured. After intravenous infusion of a sublethal dose of 5 x 10(8) live Pseudomonas aeruginosa (n = 10), pulmonary lymph flow (QL) increased 146% (P less than 0.01), and the lung lymph-to-plasma (L/P) total protein concentration ratio increased 21% (P less than 0.05). This resulted in a 208% elevation (P less than 0.01) in lung protein clearance (LPC = QL x L/P). In contrast, peripheral lymph flow and peripheral protein clearance were not altered. After intravenous infusion of a lethal dose of 5 x 10(9) live Pseudomonas (n = 7), QL rose 243-348% (P less than 0.025), whereas the lung L/P remained at base line, resulting in a 240-358% increase in LPC (P less than 0.025). Again, peripheral lymph flow and protein clearance did not increase. Plasma fibronectin declined slightly after low-dose bacterial challenge but decreased (P less than 0.001) 40% by 4-5 h after high-dose bacterial challenge. After both low- and high-dose bacterial challenge, fibronectin in pulmonary lymph increased (P less than 0.05) relative to total protein. In contrast, no change in peripheral lymph fibronectin was seen. Thus, while postoperative bacteremia increased lung protein clearance, it did not increase peripheral protein clearance, suggesting specificity with regard to the microvascular response to bacteremia.
术后菌血症可使绵羊肺血管跨血管蛋白清除率增加。我们通过比较术后菌血症对绵羊肺和股前淋巴结蛋白清除率的影响，评估这种增加的蛋白清除率是否具有肺特异性。还检测了被认为是影响血管通透性的因子——纤连蛋白。静脉注射亚致死剂量的5×10⁸活铜绿假单胞菌（n = 10）后，肺淋巴流量（QL）增加146%（P<0.01），肺淋巴与血浆（L/P）总蛋白浓度比增加21%（P<0.05）。这导致肺蛋白清除率（LPC = QL×L/P）升高208%（P<0.01）。相比之下，外周淋巴流量和外周蛋白清除率未改变。静脉注射致死剂量的5×10⁹活铜绿假单胞菌（n = 7）后，QL升高243 - 348%（P<0.025），而肺L/P保持在基线水平，导致LPC增加240 - 358%（P<0.025）。外周淋巴流量和蛋白清除率同样未增加。低剂量细菌攻击后血浆纤连蛋白略有下降，但高剂量细菌攻击后4 - 5小时下降了40%（P<0.001）。低剂量和高剂量细菌攻击后，肺淋巴中的纤连蛋白相对于总蛋白均增加（P<0.05）。相比之下，外周淋巴纤连蛋白未见变化。因此，虽然术后菌血症增加了肺蛋白清除率，但未增加外周蛋白清除率，提示对菌血症的微血管反应具有特异性。
