Regulation of Calcium Slow Channel Function by Metabolism and Cyclic Nucleotides

Abstract

The use of cultured heart cells (primary cultures) has a number of advantages over intact noncultured cardiac muscle preparations, and these advantages have been listed and discussed previously (1). The major advantages include the facts that (a) the cells can be chronically exposed to drugs and other chemicals over long periods; (b) the cells are denervated, and so direct effects of chemicals on the myocardial cells can be assessed; (c) possible effects of chemicals on changes in blood flow can be disregarded; (d) the cultures can be purified so that they consist primarily of myocytes, i.e., preponderantly one cell type; this is especially important for metabolic and biochemical assay studies; and (e) contractions of the monolayer cultures or reaggreate cultures can be directly observed under the microscope. If the cultures are prepared as monolayers, the contractions of individual cells can be observed, and the monolayers make a good preparation, consisting of two compartments (intracellular and extracellular) for ion flux studies. Reaggregate cultures have the advantage of being able to be impaled relatively easily with one or two intracellular microelectrodes for electrophysiological experiments.

The work of the authors and their colleagues reviewed and summarized in this article was supported primarily by grant HL-31942 from the National Institutes of Health.