Functional heterogeneity of the "transporter" of electrogenic ionic pump of the Lumbricus terrestris somatic myocyte membrane.

ABSTRACT

Potential created by electrogenic ionic pumps under conditions of maximum activation in a warm standard ionic medium with K(+) after preincubation in cold potassium-free solution has two components a higher ouabaine-insensitive "stationary" component, and a lower "regulatory" component sensitive to ouabaine, furosemide, and removal of Cl(-) or Ca(2+) from the medium. Functional heterogeneity of electrogenic ionic pumps is hypothesized implying the existence of two components "stationary" (not regulated extracellularly) and "regulatory" (controlled and directly related to active Cl(-) transfer).