Yonsei Med J.  1987 Mar;28(1):23-30. 10.3349/ymj.1987.28.1.23.

Effects of Vanadate on Cellular Ca2+ Movements in Guinea Pig Papillary Muscles

• Suh CK
• Park SR
• Ahn DS
• Paik KS

• KMID: 693061
• DOI: http://doi.org/10.3349/ymj.1987.28.1.23

Abstract

The effects of vanadate on cellular Ca2+ movements across the sarcolemma of cardiac muscle cells were investigated by measuring the intracellular and extracellular Ca2+ activities of guinea pig papillary muscle with Ca2+-selective electrodes. During the rest period following a steady-state of 2 contractions per second the extracellular Ca2+ concentration was increased over the basal level within a minute. During the rest period Ca2+ was transported across the sarcolemma into the extracellular space. Vanadate decreased the change in extracellular Ca2+ concentration during the rest period implying that the Ca2+ efflux across the sarcolemma was decreased by vanadate. Vanadate increased intracellular Ca2+ activities significantly (from 1.9 X 10(-7) M to 10(-6)M) resulting in an increase in resting tension. These results suggest that vanadate decreases Ca2+ efflux from the cells into the extracellular space by blocking Ca2+ transport across the sarcolemma, possibly blocking the Na+-Ca2+ exchange transport.

Keyword

Guinea pig papillary muscle; Na+-Ca2+ exchange transport; Ca2+-selective electrodes; intracellular Ca2+ activity; vanadate

MeSH Terms

Animal
Calcium/metabolism*
Female
Guinea Pigs
Ion Channels/drug effects*
Male
Membrane Potentials/drug effects
Papillary Muscles/drug effects*
Vanadates
Vanadium/pharmacology*