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THE EFFECT OF ADRENALIN ON MUSCULAR FATIGUE IN LEPTODACTYLUS OCELLATUS (L. GIR.) AND IN BUFO MARINUS
Author(s) -
Guglielmetti John
Publication year - 1919
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0370-2901
DOI - 10.1113/expphysiol.1919.sp000257
Subject(s) - toad , bufo marinus , bufo , perfusion , medicine , anatomy , biology , endocrinology , anesthesia
1. Subcutaneous or intravenous injection of adrenalin in the frog, Leptodactylus ocellatus, and the toad, Bufo marinus, produces recovery of muscular contractions which have been abolished by previous fatigue. Perfusion experiments show the same result. 2. Within certain limits, the period of duration of the recovery curve depends upon the quantity of adrenalin used, on the frequency of excitation, and on the weight lifted by the muscle. 3. The height of the recovery curve is generally lower than that of the initial curve, but sometimes higher. 4. Given sufficient doses, recovery may be obtained in muscles which have been wholly exhausted, but if a certain interval has elapsed after the fatigue was complete, this result is inconstant. 5. If the first dose is small and the second one much greater (ten times), two consecutive recoveries can be obtained. 6. A dose of adrenalin so small as to be unable to influence the fatigue curve may nevertheless render the muscle less sensitive to a succeeding dose. 7. The manner in which the stimulus is applied, whether through the nerve or directly to the muscle, does not modify the phenomena. 8. When administered by the perfusion method, similar results are obtained, but fatigue supervenes much more rapidly. 9. Recovery is more usually obtained when the adrenalin is made to act early upon the preparation. 10. Frogs are more sensitive to adrenalin when they are fasting. 11. The sensitivity of the frog, Leptodactylus ocellatus, is about five times greater than that of the toad, Bufo marinus.