Isolation and enrichment of Ca2+-tolerant myocytes for biochemical experiments from guinea-pig heart

Isolated myocytes for biochemical experiments must be homogeneous and highly enriched in viable cells. For cardiac myocytes, isolation of Ca2+-tolerant cells in high yield and with good viability has been possible from rat. This paper describes myocyte isolation and enrichment procedures which are effective for several species including guinea-pig and rat. New methods for selection of collagenase and viable cells are presented. Using Ca2+-tolerant myocytes obtained from guinea-pig heart and enriched in viable cells, dihydropyridine binding sites are shown to be accessible only in depolarized cells.