D'Angelo E, Bellemare F
Istituto di Fisiologia Umana I, Cattedra VI, Università di Milano, Italy.
Respir Physiol. 1990 Feb;79(2):177-93. doi: 10.1016/0034-5687(90)90017-s.
In anesthetized dogs with progressive hypercapnia, the relationships between tidal volume (VT) or occluded inspiratory esophageal pressure swings (Pes) and diaphragm (Edi) or thoracic inspiratory muscle (Etm) peak electrical activity were determined after either cordotomy at C7-T1 or bilateral phrenicotomy, and used together with the Etm vs Edi relationships established in intact and vagotomized dogs to estimate the contribution of each muscle group to VT and Pes observed under the latter conditions. Etm was obtained as the mean of scalene, 2nd and 5th parasternal peak activity, the relationships between these activities being the same under all conditions. In supine and head-up phrenicotomized dogs, VT and Pes increased linearly with Etm and were unaffected by body position. After cordotomy, VT and Pes increased progressively less with increasing Edi and at any Edi were smaller in the head-up posture. Diaphragm relative contribution to VT and Pes was greater when supine than head-up and greater after than before vagotomy, but in all cases it decreased with increasing chemical drive. That of the thoracic inspiratory muscles increased with chemical drive and eventually became equal to (supine) or larger than (head-up) diaphragm contribution.
在患有进行性高碳酸血症的麻醉犬中，在C7 - T1水平进行脊髓切断术或双侧膈神经切断术后，测定潮气量（VT）或吸气末食管闭塞压力波动（Pes）与膈肌（Edi）或胸部吸气肌（Etm）峰值电活动之间的关系，并将其与完整和迷走神经切断犬中建立的Etm与Edi关系一起用于估计在后者条件下每个肌肉群对观察到的VT和Pes的贡献。Etm作为斜角肌、第二和第五胸骨旁肌峰值活动的平均值获得，在所有条件下这些活动之间的关系相同。在仰卧位和头高位膈神经切断的犬中，VT和Pes随Etm呈线性增加，且不受体位影响。脊髓切断术后，随着Edi增加，VT和Pes的增加逐渐减少，并且在任何Edi水平下，头高位时的值较小。膈肌对VT和Pes的相对贡献在仰卧位时比头高位时更大，迷走神经切断术后比术前更大，但在所有情况下，它随着化学驱动增加而降低。胸部吸气肌的贡献随着化学驱动增加，最终等于（仰卧位）或大于（头高位）膈肌的贡献。
