Related Experiment Video
Updated: Aug 22, 2026

Standardized Rat Coronary Ring Preparation and Real-Time Recording of Dynamic Tension Changes Along Vessel Diameter
Published on: June 16, 2022
Callipeltin A: sodium ionophore effect and tension development in vascular smooth muscle
Lucia Trevisi1, Gabriella Cargnelli, Giulio Ceolotto
1Department of Pharmacology and Anaesthesiology, University of Padua, Largo E. Meneghetti 2, 35131 Padua, Italy.
Abstract:
Callipeltin A is a cyclic depsidecapeptide isolated from the marine sponges Callipelta sp. and Latrunculia sp. that has been previously shown to increase the force of contraction of guinea-pig atria through the inhibition of Na+/Ca2+ exchanger (NCX). We investigated the effect of callipeltin A on guinea-pig aortic rings contracted by procedures that activate NCX in "calcium entry mode". Callipeltin A did not inhibit these contractions. Resting aorta responded to callipeltin A with a remarkable contraction that was concentration-dependent (EC50 0.44microM). This contraction was not inhibited by the calcium channel blocker verapamil and was not mediated by the activation of alpha-adrenergic or endothelin-1 receptors. Pre-incubation of aortic rings with 0.5mM amiloride, an inhibitor of NCX, completely prevented callipeltin A-induced contraction. Furthermore, callipeltin A (EC50 0.51microM) increased Na+ efflux of Na-loaded erythrocytes. 1H and 13C NMR resonances of callipeltin A revealed small but significant changes in the titration with K+ and Na+ salts. It is suggested that the effect of callipeltin A on cardiac and vascular preparations is linked to a Na-ionophore action.
More Related Videos
07:56Isolation of Intrapulmonary Artery and Smooth Muscle Cells to Investigate Vascular Responses
Published on: June 8, 2022
09:54Multifunctional, Micropipette-based Method for Incorporation And Stimulation of Bacterial Mechanosensitive Ion Channels in Droplet Interface Bilayers
Published on: November 19, 2015
Related Concept Videos
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Patch Clamp
In this method, a glass micropipette containing electrolyte solution is tightly sealed against a small portion of the cell membrane. As a result, a patch of the cell...
Tension Response at Adherens Junctions
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...
Tonicity in Plants
Tonicity
Tonicity describes the capacity of a cell to lose or gain water depending on the solute...
Tonicity in Plants
Intracellular Signaling Affects Focal Adhesions
Some...