Paradoxical relationship between substrates and agonist-induced contractions of opossum esophageal body and sphincter in vitro.
Paradoxical relationship between substrates and agonist-induced contractions of opossum esophageal body and sphincter in vitro.
复制标题
底物与激动剂诱导的负鼠食管体和括约肌体外收缩之间的矛盾关系。
DOI：
10.1007/bf01297447
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发表时间：
1991
影响因子：
3.1
通讯作者：
Christensen,J
中科院分区：
文献类型：
--
作者：
Percy,WH;Sutherland,J;Christensen,J
研究了食管体和下食管括约肌利用底物支持激动剂诱导的收缩的能力的可能差异。来自负鼠食管的纵向、环形和下食管括约肌的条带首先收缩至乙酰胆碱、组胺然后将组织暴露于5×10− 4 M卡巴胆碱和15%O2 - 5%CO2 -80% N2气体混合物90分钟。然后用一种替代底物和95%O2 - 5%CO2再平衡3小时。再次记录对初始激动剂剂量的反应，并与对照组进行比较。替代底物为：2-脱氧葡萄糖、葡萄糖、果糖1-6二磷酸、丙酮酸、乳酸、乙酸、丁酸、辛酸、组氨酸、亮氨酸、天冬氨酸、丙氨酸、琥珀酸、乙酰丙酮和β-羟基丁酸。所获得的结果表明，三种肌肉类型使用这些底物的能力存在质的差异。然而，更重要的是，任何一种底物支持收缩的能力都是用于刺激肌肉的激动剂的功能。因此，证据表明，并非所有的药理学受体都能平等地获得细胞内的能量来源。
Possible differences in the abilities of esophageal body and lower esophageal sphincter muscles to utilize substrates to support agonist-induced contractions were studied. Strips of longitudinal, circular, and lower esophageal sphincter muscle from the opossum esophagus were first contracted to approximately 70% of the maximal contraction elicited by acetylcholine, histamine, or substance P. The tissues were then exhausted by exposure to 5×10−4M carbachol and a 15% O2-5% CO2-80% N2gas mixture for 90 min. They were next reequilibrated with one of a number of alternative substrates and 95% O2-5% CO2for 3 hr. Responses to the initial agonist doses were again noted and compared to controls. The alternative substrates were: 2-deoxyglucose, glucose, fructose 1–6 diphosphate, pyruvate, lactate, acetate, butyrate, caprylate, histidine, leucine, aspartate, alanine, succinate, acetoacetone, and β-hydroxybutyrate. The results obtained show qualitative differences in the ability of the three muscle types to use these substrates. More importantly, however, the ability of any one substrate to support contractions was a function of the agonist used to stimulate the muscle. The evidence suggests, therefore, that not all pharmacologic receptors have equal access to intracellular energy sources.