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The effect of adenosine on the release of the transmitter from the phrenic nerve of the rat
Author(s) -
Ginsborg B. L.,
Hirst G. D. S.
Publication year - 1972
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1972.sp009916
Subject(s) - adenosine , theophylline , diaphragm (acoustics) , phrenic nerve , chemistry , neuromuscular transmission , neuromuscular junction , biophysics , anesthesia , medicine , respiratory system , biology , biochemistry , neuroscience , physics , acoustics , loudspeaker
1. The action of adenosine on neuromuscular transmission has been studied on the rat phrenic nerve—diaphragm preparation. 2. Adenosine (0·025–10 m M ) reversibly reduced the quantum content of end‐plate potentials and the frequency of miniature end‐plate potentials to about half the control values in preparations in which transmission was blocked with high Mg 2+ and/or low Ca 2+ concentrations. Where transmission was blocked with tubocurarine, the amplitude of end‐plate potentials was reduced to about half the control values by adenosine. 3. In solutions with very low Ca 2+ concentrations (no added Ca 2+ and 1 m M ‐EGTA) adenosine had a smaller effect on the frequency of miniature end‐plate potentials. 4. The effect of adenosine (0·025 and 0·05 m M ) was abolished by theophylline (1·8 m M ). 5. The results are discussed in relation to the increase in cyclic AMP in brain slices caused by adenosine and the abolition of this effect by theophylline (Sattin & Rall, 1970).