Cyclopiazonic acid and thapsigargin reduce Ca2+ influx in frog skeletal muscle fibres as a result of Ca2+ store depletion

Acta Physiologica Scandinavica
W Même, C Léoty

Abstract

We have investigated the influence of the sarcoplasmic reticulum (SR) Ca2+ content on the retrograde control of skeletal muscle L-type Ca2+ channels activity by ryanodine receptors (RyR). The effects of cyclopiazonic acid (CPA) and thapsigargin (TG), two structurally unrelated inhibitors of SR Ca(2+)-adenosine triphosphatase (ATPase), were examined on the SR Ca2+ content, the calcium current and contraction in single frog semitendinosus fibres using the double mannitol-gap technique. At moderate concentrations that only partially inhibited Ca2+ sequestration by the SR, CPA (2-4 microM) induces a concentration dependent depression of contraction and Ca2+ current amplitudes. When Ba2+ is the charge carrier, the inward current is not changed by CPA suggesting that this Ca(2+)-pump inhibitor does not directly affect dihydropyridine Ca2+ channels. Similar effects were obtained with TG (1-5 microM). Changes in Ca2+ currents and contraction were accompanied by a reduced Ca2+ loading of the SR. We attribute the modulation of the Ca2+ current to the selective inhibition of the SR Ca2+ ATPase, resulting in a decreased Ca2+ release and thereby a reduced activation of calcium inward currents. This is therefore taken to represent a calcium ...Continue Reading

References

May 1, 1983·The Journal of Physiology·G CotaE Stefani
Oct 1, 1983·The Journal of General Physiology·P L Donaldson, K G Beam
Dec 1, 1982·The Journal of Physiology·D Potreau, G Raymond
Jun 1, 1980·The Journal of Physiology·D Potreau, G Raymond
Oct 1, 1993·Pflügers Archiv : European journal of physiology·D FeldmeyerP Zöllner
Jan 1, 1995·Naunyn-Schmiedeberg's Archives of Pharmacology·V BuryiT Godfraind
Apr 1, 1993·Journal of Muscle Research and Cell Motility·S BlaineauO Rougier
Nov 1, 1995·Journal of Molecular and Cellular Cardiology·A BadaouiC Léoty
Mar 1, 1996·Acta Physiologica Scandinavica·A A BendersJ H Veerkamp
Jun 20, 1998·Pflügers Archiv : European journal of physiology·A M Duke, D S Steele
Jun 5, 1998·The Journal of Biological Chemistry·J NakaiK G Beam

❮ Previous
Next ❯

Citations

May 5, 2007·Circulation Research·Yue-Kun JuDavid G Allen
Feb 27, 2019·Journal of Muscle Research and Cell Motility·Masatoshi KomatsuMitsuhiko Yamada
Dec 26, 2006·Neuroscience and Behavioral Physiology·G A NasledovYu V Zhitnikova
May 22, 2003·American Journal of Physiology. Endocrinology and Metabolism·Matthew J WattDavid J Dyck

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.