The influence of stretch on the membrane potential of the striated muscle fiber

✍ Scribed by Ling, G. ;Gerard, R. W.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1949
• Tongue: English
• Weight: 441 KB
• Volume: 34
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030340305

✦ Synopsis

Since a change in length is the primary action of muscle, much attention llas been given to alterations in its state resulting from passive stretch. Metabolism, as indicated by heat production (Feng, '32 ; von Euler, '35) , respiratory exchange (Meyerhof et al., '33 ; Eddy and Downs, '21b), and lactic acid formation (Ernst, '31), is increased in a stretched muscle. This extra energy, f o r whatever reason needed, suffices to maintain creatin phosphate at the normal level (Katz, '34). Stretch also hastens fatiguability (Eddy and Downs, '2la) and swelling in Ringer solution (Meyerhof and Mohle, ' 3 3 ) , but lowers excitability (Asmussen, '36) and the speed of coiiduction of the contraction wave (E'ischer, '26) and of action potential (Hieronymus, '29 ; Wilslia, '39). Much and conflict- ing work has been reported on changes in the size of action and demarcation potentials. "Spike" height was found by most workers (du Bois Reymond, 1849 ; Schenk, 1896 ; Lamansky, 1870) to increase on stretch ; by one group (Forbes et al., '23), to remain unchanged. Demarcation potential has been found to rise (Einthoven and Rademaker, '16; de Meyer, '21; Katz,