The Na+-Ca2+ exchange mechanism as a regulator of post rest contractions in cardiac muscle.
The effects of external Na+ concentration and stimulation rate changes on the post rest contractions of rat myocardium were studied. An increase in external Na+ concentration or in stimulation rate causes relative potentiation of the post rest contractions, suggesting that the sarcolemmal Na+-Ca2+ exchange mechanism affects the magnitude of the potentiation of post rest contractions.
Abreu
G R
GR
Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brasil.
Vassallo
D V
DV
Mill
J G
JG
D000818:Animals; D001794:Blood Pressure; D002118:Calcium / Q000378:metabolism*; D007537:Isometric Contraction; D009200:Myocardial Contraction; D010210:Papillary Muscles / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism*
D012964:Sodium; D002118:Calcium