Grumelli Sandra
Centro de Investigaciones en Medicina Respiratoria, Universidad Católica de Córdoba, Cordoba, Argentina.
Pulmonary Division of the Brigham and Women's Hospital, Harvard Medical School, Boston, USA.
Curr Respir Med Rev. 2016;12(2):167-174. doi: 10.2174/1573398X12999160506104327.
Although exacerbations of chronic obstructive pulmonary disease produced by infections are a major cause of death, the molecular mechanism that produces them is not well known. Here we focused on the energetic basis of dyspnoea, hypercapnia and acidosis symptoms.
We used an in vivo exacerbation model exposing mice to cigarette smoke and LPS, to mimic emphysema and infections, and choline challenges to trigger exacerbations, that showed 31% increased in the airway resistance for naïve mice and 250% for smoke/LPS treatment. Tissue resistance was increased 32%, in naïve mice, and 169% for smoke/LPS treatment. A decreased tissue elastance, was confirmed by decreased collagen content and increased alveoli chord length. Consequently, the O demanded was 260% greater for smoke/LPS treated mice, to provide the energy required to pump the same volume of air then for naïve mice. The extra CO produced per ml of air pumped caused hypercapnia and acidosis by 4% decrease in pH.In addition, the bacteria grown with choline had a decrease of 67% in phosphate, 23% ATP and 85% phospholipids with an increase of 57% in polyphosphates, 50% carbohydrates, 100% LPS, consuming 45% less energy relative to the bacteria grown with succinate.
choline, released by , triggers exacerbation symptoms by increasing lung resistance, O consumption and producing more pCO in blood with dyspnea, hypercapnia and acidosis. The energetic shift of decreased O bacterial demand and increased lung demand benefits the infection, thus restoring the energetic balance on the host will favor eradication.
尽管感染引发的慢性阻塞性肺疾病急性加重是主要死因之一,但其产生的分子机制尚不清楚。在此,我们聚焦于呼吸困难、高碳酸血症和酸中毒症状的能量基础。
我们使用一种体内急性加重模型,将小鼠暴露于香烟烟雾和脂多糖中,以模拟肺气肿和感染,并通过胆碱激发来引发急性加重。结果显示,未处理小鼠的气道阻力增加了31%,而烟雾/脂多糖处理组增加了250%。未处理小鼠的组织阻力增加了32%,烟雾/脂多糖处理组增加了169%。通过胶原含量减少和肺泡弦长增加证实了组织弹性降低。因此,烟雾/脂多糖处理的小鼠为泵出相同体积空气所需的氧气需求量比未处理小鼠高260%。每泵出1毫升空气产生的额外二氧化碳导致血液pH值下降4%,从而引起高碳酸血症和酸中毒。此外,与琥珀酸培养的细菌相比,胆碱培养的细菌磷酸盐减少67%、三磷酸腺苷减少23%、磷脂减少85%,而多磷酸盐增加57%、碳水化合物增加50%、脂多糖增加100%,能量消耗减少45%。
由……释放的胆碱通过增加肺阻力、氧气消耗以及在血液中产生更多二氧化碳,引发呼吸困难、高碳酸血症和酸中毒等急性加重症状。细菌氧气需求减少和肺需求增加的能量转变有利于感染,因此恢复宿主的能量平衡将有助于根除感染。