The modes of action of the modulatory compounds octopamine, 5-hydroxytryptamine (5-HT) and proctolin on the frequency of the myogenic rhythm of the extensor-tibiae muscle of the hindleg of the locust, Schistocerca americana gregaria, have been investigated. 5-HT and proctolin increase the frequency of the myogenic rhythm and the results of the present study suggest that they may mediate their effects by increasing the levels of cyclic AMP in the pacemaker of the myogenic bundle. In contrast, octopamine reduces the frequency of the myogenic rhythm and appears to mediate its effects by a mechanism that does not involve an elevation of cyclic AMP. A number of other possible mechanisms for the action of octopamine are discussed.
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JOURNAL ARTICLE| 01 May 1984
Studies on the mode of action of octopamine, 5-hydroxytryptamine and proctolin on a myogenic rhythm in the locust
P. D. Evans
Online Issn: 1477-9145
Print Issn: 0022-0949
© 1984 by Company of Biologists
J Exp Biol (1984) 110 (1): 231–251.
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P. D. Evans; Studies on the mode of action of octopamine, 5-hydroxytryptamine and proctolin on a myogenic rhythm in the locust. J Exp Biol 1 May 1984; 110 (1): 231–251. doi: https://doi.org/10.1242/jeb.110.1.231
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