Figure 5

Assessment of endothelial function in mice that survived or did not survive 48 hours of sepsis. CLP was performed in C57BL/6 young mice as described in Methods. Following CLP, mice were constantly monitored for 48 hours. In our model the survival rate at 48 hours is approximately 50%. Thoracic aortas from the mice that did not survive the 48 hours of sepsis were harvested at the exact time of death, placed in 5 ml organ baths filled with oxygenated Krebs-Henseleit solution at 37°C and mounted onto isometric force transducers to assess for vascular response to endothelium-derived nitric oxide (NO) by acetylcholine (Ach) stimulation. Five death events were recorded, aortic rings from the five non-survivors were used. The mean time of survival (or tissue harvesting) was 39 hours. Survivors were euthanized at 48 hours of sepsis by opening the chest cavity. In a sequent study, a similar approach was used for the assessment and comparison of endothelial function in survivor versus non-survivor aged mice. Since the survival rate at 48 hours of CLP is only 80% in the case of the aged mice, we restricted the CLP to a 24-hour time frame. Aortic rings were harvested from five different mice. The mean time of survival (or tissue harvesting) in this group was 17 hours. The survivors were euthanized 24 hours following CLP. Please note the marked degree of endothelial dysfunction in the non-survivor group of animals (Panel A, B and C). Concentration response curves to the NO donor sodium nitroprusside (SNP) were performed to ensure the integrity of the smooth muscle and the viability of the tissue preparations (Panel D). (^*P <0.05 vs. corresponding survivors). CLP, cecal ligation and puncture.