Effects of Vanadate on Cellular Ca2+ Movements in Guinea Pig Papillary Muscles.
- Author:
Chang Kook SUH
1
;
So Ra PARK
;
Duck Sun AHN
;
Kwang Sei PAIK
Author Information
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords: Guinea pig papillary muscle; Na+-Ca2+ exchange transport; Ca2+-selective electrodes; intracellular Ca2+ activity; vanadate
- MeSH: Animal; Calcium/metabolism*; Female; Guinea Pigs; Ion Channels/drug effects*; Male; Membrane Potentials/drug effects; Papillary Muscles/drug effects*; Vanadates; Vanadium/pharmacology*
- From:Yonsei Medical Journal 1987;28(1):23-30
- CountryRepublic of Korea
- Language:English
- 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.
