Calcium currents and contraction in frog atrial trabeculae.
The properties of two types of calcium current (ICa(T) and ICa(L)) and their relationship with contraction were studied in isolated frog atrial trabeculae using the double mannitol gap technique. In Ringer solution containing TTX the calcium currents observed are similar to the ICa(T) and ICa(L) found in single frog atrial cells. The results obtained by using inorganic calcium channel blockers have shown that the phasic contraction appears only when ICa(T) and ICa(L) are simultaneously present. It is proposed that ICa(T) loads the sarcoplasmic reticulum (SR) while ICa(L) triggers Ca2+ release from the SR.
Badaoui
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A
Laboratory of General Physiology, URA CNRS 1340, University of Nantes, France.
Léoty
C
C
D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D006325:Heart Atria / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008345:Manganese / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D009532:Nickel / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D011893:Rana esculenta
D002121:Calcium Channel Blockers; D002104:Cadmium; D008345:Manganese; D009532:Nickel; D002118:Calcium