Injected cyclic AMP increases ciliary beat frequency in conjunction with membrane hyperpolarization.

T Hennessey; H Machemer; D L Nelson

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PubMed · 2581782

Injected cyclic AMP increases ciliary beat frequency in conjunction with membrane hyperpolarization.

T Hennessey·H Machemer·D L Nelson

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Abstract

Injections of cyclic AMP (cAMP) and 8-Br-cAMP into Paramecium and external application of isobutylmethylxanthine (IBMX), an inhibitor of cAMP breakdown, to these cells increased the frequency of ciliary beating and hyperpolarized the membrane potential. When the membrane potential was held equal to the resting potential under voltage clamp, the same experimental conditions which serve to increase intracellular cAMP did not raise the ciliary frequency. We conclude that cAMP is presumably not the direct mediator of the hyperpolarization-induced ciliary activation, although it may be associated with this motor response.

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1-Methyl-3-isobutylxanthine Animals Cilia Cyclic AMP Membrane Potentials Movement Paramecium Comparative Study Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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T Hennessey, H Machemer, D L Nelson. 1985. Injected cyclic AMP increases ciliary beat frequency in conjunction with membrane hyperpolarization.. https://pubmed.ncbi.nlm.nih.gov/2581782/

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