Effects of Dibutyryl Cyclic Adenosine 3′,5′‐monophosphate and Theophylline on the Bullfrog Sympathetic Ganglion Cells

Abstract

1 Effects of dibutyryl cyclic adenosine 3′,5′‐monophosphate (dibutyryl cyclic AMP) and theophylline on bullfrog sympathetic ganglion cells were examined in order to test the hypothesis that cyclic AMP is essential for the generation of slow inhibitory postsynaptic potentials (i.p.s.ps) in these cells. 2 In the absence or presence of theophylline, dibutyryl cyclic AMP did not hyperpolarize but rather tended to depolarize ganglia that were hyperpolarized by adrenaline. 3 Theophylline augmented neither the P‐potential (slow i.p.s.p.) nor adrenaline‐induced hyperpolarization. 4 Thus, cyclic AMP does not seem to be essential for the generation of the slow i.p.s.p., at least in amphibian sympathetic ganglion cells.

Cyclic adenosine 3′,5′‐monophosphate and β‐effects in rat isolated superior cervical ganglia

“…Brown etal., 1979, andMcAfee et al, 1980, for further discussion of this point). External application of cyclic AMP or its derivatives has usually been observed to produce either a ganglion hyperpolarization (McAfee & Greengard, 1972;Machova & Kristofova, 1973;, or no clear effect (Dun, Kaibara & Karczmar, 1977;Gallagher & Shinnick-Gallagher, 1977;Busis, Weight & Smith, 1978), though a depolarization has been reported by Akasu & Koketsu (1977) in frog ganglia and by Hsu & Mclsaac (1978) in rat ganglia. Such a depolarization was occasionally observed in the present experiments, but this was antagonized by theophylline suggesting that, like the previouslyobserved hyperpolarization it resulted from activation of external adenosine receptors.…”

Adenosine triphosphate facilitates the Na+-K+ pump of frog skeletal muscle fibres.

“…been proposed on the basis that slow IPSP is mediated by cyclic AMP, the second messenger of catecholamine in sympathetic ganglia (McAfee and Greengard, 1972). According to electrophysiological studies of the effect of cyclic AMP on sympathetic ganglion cells, however, the electrogenic Nam pump of these cells does not appear to be stimulated by cyclic AMP (Akasu and koketsu, 1977). Further, direct experimental evidence showing that cyclic AMP does not stimulate Na+ pump is presented in this study.…”