Hydrolysis of Acetylcholine by Frog Skeletal Muscle

  • R. Miledi
  • P. C. Molenaar
  • R. L. Polak
Part of the Advances in Behavioral Biology book series (ABBI, volume 25)


There are several reports showing that intact muscles hydrolyze acetylcholine (ACh) at a much slower rate than their homogenates (see for instance Refs. 4,9,10,16). Marnay and Nachmansohn (10) suggested that in intact muscle the relative slowness of the hydrolysis of added ACh by Cholinesterase (ChE) is caused by slow diffusion of ACh through the muscle tissue. In mammalian muscle the difference in ChE activity between intact and homogenized preparations has been attributed, in part or fully, to the liberation of intracellular ChE by the homogenization. This and other considerations led to the suggestion that the data obtained with intact preparations are more relevant to the physiological function of the enzyme at the endplates than those obtained with homogenates (9,16). On the other hand, it could be that the in situ synaptic activity of ChE, the “functional activity,” of the enzyme, is severely distorted by hindred diffusion, when it is measured with exogenous substrates on intact tissue.


Intact Tissue Homogenize Muscle Sartorius Muscle Frog Skeletal Muscle Intact Muscle 
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  1. 1.
    Betz, W. and Sakmann, B. (1973): J. Physiol. 230:673–688.Google Scholar
  2. 2.
    Buckley, G.A. and Heaton, J. (1968): J. Physiol. 199:743–749.Google Scholar
  3. 3.
    Couteaux, R. (1963): Proc. R. Soc. Lond. B. 158:457–480.CrossRefGoogle Scholar
  4. 4.
    Feng, T.P. and Ting, Y.C. (1938): Chin. J. Physiol. 13:141–144.Google Scholar
  5. 5.
    Hall, Z.W. and Kelly, R.B. (1971): Nature New Biol. 232:62–63.Google Scholar
  6. 6.
    Katz, B. and Kuffler, S.W. (1941): J. Neuro Physiol. 6:99–110.Google Scholar
  7. 7.
    Katz, B. and Miledi, R. (1977): Proc. R. Soc. Lond. B. 196:59–72.Google Scholar
  8. 8.
    Liu, A.Y.C. and Mittag, T. (1974): Molec. Pharmacol, 10:283–292.Google Scholar
  9. 9.
    Lund Karlsen, R. and Fonnum, F. (1977): J. Neurochem. 29:151–156.CrossRefGoogle Scholar
  10. 10.
    Marnay, A. and Nachmansohn, D. (1938): J. Physiol. 92:37–47.Google Scholar
  11. 11.
    Miledi, R. (1960): J. Physiol. 151:1–23.Google Scholar
  12. 12.
    Miledi, R. (1964): Nature (Lond) 204:293–295.CrossRefGoogle Scholar
  13. 13.
    Miledi, R., Molenaar, P.C. and Polak, R.L. (1977): Proc. R. Soc. Lond. B. 197:285–297.Google Scholar
  14. 14.
    Miledi, R., Molenaar, P.C. and Polak, R.L. (1977): In Chol inergic Mechanisms and Psychopharmacology, (ed), D.J. Jenden, Plenum Press, New York, pp. 377–386.Google Scholar
  15. 15.
    Miledi, R., Molenaar, P.C. and Polak, R.L. (1980): J. Physiol. 309:199–214.Google Scholar
  16. 16.
    Mittag, T.W., Ehrenpreis, S. and Hehir, R.M. (1971): Biochem. Pharmacol. 20:2263–2273.CrossRefGoogle Scholar
  17. 17.
    Namba, T. and Grob, D. (1970): J. Clin. Invest. 49:936–942.CrossRefGoogle Scholar
  18. 18.
    Pezard, A. and May, R.M. (1937): C.R. Soc. Biol. Paris 124:1081–1083.Google Scholar
  19. 19.
    Polak, R.L. and Molenaar, P.C. (1974): J. Neurochem. 22:1295–1297.Google Scholar
  20. 20.
    Potter, L.T. (1967): J. Pharmacol. Exp. Ther. 156:500–506.Google Scholar

Copyright information

© Plenum Press, New York 1981

Authors and Affiliations

  • R. Miledi
    • 1
  • P. C. Molenaar
    • 2
  • R. L. Polak
    • 3
  1. 1.Department of BiophysicsUniversity College LondonUK
  2. 2.Department of Pharmacology, Sylvius LaboratoriesLeiden University Medical CenterLeidenThe Netherlands
  3. 3.Medical Biological Laboratory TNORijswijkThe Netherlands

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