HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Devlin, C. L. Search for Related Content PubMed PubMed Citation Articles by Devlin, C. L. Related Collections Molluscs Physiology

5-Hydroxytryptamine Stimulates Net Ca²⁺ Flux in the Ventricular Muscle of a Mollusc (Busycon canaliculatum) During Cardioexcitation

Department of Biology, Penn State University, Abington College, Abington, Pennsylvania 19001

E-mail: cld5{at}psu.edu

Noninvasive, self-referencing calcium (Ca²⁺) electrodes were used to study the mechanisms by which 5-hydroxytryptamine (5-HT) affects net Ca²⁺ flux across the sarcolemma of myocytes from ventricular trabeculae (from a marine gastropod, Busycon canaliculatum). Treatment of isolated trabeculae with 5-HT causes a net Ca²⁺ efflux, which is 30% blocked by verapamil. These findings suggest that the efflux is in part the result of a previous Ca²⁺ influx through L-type Ca²⁺ channels and is due to a rapid Ca²⁺ extrusion mechanism inherent to the sarcolemma of these myocytes. 5-HT-induced net Ca²⁺ efflux is also reduced by about 40% by treatment with a sodium (Na⁺)-free, lithium (Li⁺)-substituted saline, which shuts down the Na-Ca exchanger during Ca²⁺ extrusion. Cyclopiazonic acid (CPA), an inhibitor of the sarcoplasmic reticulum (SR) Ca²⁺ ATPase, almost completely abolishes the 5-HT-induced net Ca²⁺ efflux, suggesting that the SR rather than the extracellular pool is the primary Ca²⁺ reservoir serving 5-HT-induced excitation.

This article has been cited by other articles:

				B.-G. Tuo, Z. Sellers, P. Paulus, K. E. Barrett, and J. I. Isenberg 5-HT induces duodenal mucosal bicarbonate secretion via cAMP- and Ca2+-dependent signaling pathways and 5-HT4 receptors in mice Am J Physiol Gastrointest Liver Physiol, March 1, 2004; 286(3): G444 - G451. [Abstract] [Full Text] [PDF]