Schulze-Delrieu K, Lepsien G
Gastroenterology. 1982 Apr;82(4):720-4.
We studied the effect of acidosis on nerve-muscle preparations from the opossum stomach and esophagus. All muscle strips were mounted in superfusion chambers and spontaneous contractile activity was recorded from longitudinal and transverse gastric muscle strips. Mechanical activity in esophageal and oblique gastric muscle strips was elicited by electrical stimulation of intrinsic nerves. The contractile activity of all types of strips changed when the pH of the superfusate was lowered for 30 min from 7.4 to 7.0. The baseline tension rose in strips from the lower esophageal sphincter and in oblique gastric muscle strips, and a baseline tension occurred de novo in longitudinal esophageal strips. Muscle relaxation was also impaired in these three types of strips. The amplitude of contractions declined in transverse strips from the esophageal body and in transverse and longitudinal strips from the stomach. The frequency of spontaneous contractions and of the pacesetter potential as recorded by extracellular electrodes was also reduced by acidosis in muscle strips from the stomach. Similar but less marked changes occurred when the pH was lowered from 7.4 to 7.2 for 30 min. Most changes related to a pH of 7.0 became irreversible after superfusion periods of more than 2 h. These findings indicate that acidosis alters a variety of neuromuscular functions and that its effects are determined by the electrical and contractile characteristics and the intrinsic innervation of individual segments and layers of the gut muscle coat.
我们研究了酸中毒对负鼠胃和食管神经肌肉标本的影响。所有肌肉条均安装在灌流室中，从胃纵行和横行肌肉条记录自发收缩活动。通过电刺激内在神经引发食管和胃斜行肌肉条的机械活动。当灌流液的pH值从7.4降低30分钟至7.0时，所有类型肌肉条的收缩活动均发生改变。食管下括约肌的肌肉条和胃斜行肌肉条的基线张力升高，食管纵行肌肉条出现新的基线张力。这三种类型的肌肉条的肌肉松弛也受到损害。食管体部横行肌肉条以及胃的横行和纵行肌肉条的收缩幅度下降。酸中毒也使胃肌肉条中通过细胞外电极记录的自发收缩频率和起搏电位频率降低。当pH值从7.4降低30分钟至7.2时，出现类似但不太明显的变化。在超过2小时的灌流期后，大多数与pH值7.0相关的变化变得不可逆。这些发现表明，酸中毒会改变多种神经肌肉功能，其影响取决于肠道肌层各节段和各层的电特性、收缩特性以及内在神经支配。
