Translator Disclaimer
1 November 2005 Photosensitive Signal Transduction Induces Membrane Hyperpolarization in Paramecium bursaria
Author Affiliations +
Abstract

The protozoan ciliate Paramecium bursaria exhibits membrane hyperpolarization in response to photostimulation, accompanied with an increased swimming speed. The external addition of cyclic nucleotide phosphodiesterase (PDE) inhibitors, either theophylline (1,3-dimethylxanthine) or 3-isobutyl-1-methylxanthin (IBMX), increased in both amplitudes of the membrane hyperpolarization and the increase in swimming speed. Moreover, the addition of membrane permeable cyclic nucleotide analogs, either 8-bromo-adenosine 3′,5′-cyclic monophosphate (Br-cAMP) or 8-Br-guanosine 3′,5′-cyclic monophosphate (Br-cGMP), increased these amplitudes. On the other hand, the addition of l-cis-diltiazem, known to block the conductance of cyclic nucleotide–gated channels, partially decreased both amplitudes of the membrane hyperpolarization and the increase in swimming speed. An enzyme immunoassay of cellular cyclic nucleotide contents showed that photostimulation induced a rapid increase in adenosine 3′,5′-cyclic monophosphate (cAMP), but little increase in guanosine 3′,5′-cyclic monophosphate (cGMP), raising the possibility that a rapid increase in cAMP mediates the light-induced hyperpolarization in P. bursaria.

Atsushi Mitarai and Yasuo Nakaoka "Photosensitive Signal Transduction Induces Membrane Hyperpolarization in Paramecium bursaria," Photochemistry and Photobiology 81(6), 1424-1429, (1 November 2005). https://doi.org/10.1562/2005-05-23-RA-537
Received: 23 May 2005; Accepted: 1 July 2005; Published: 1 November 2005
JOURNAL ARTICLE
6 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top