Evidence from aequorin for injury of metabolically inhibited myocytes independently of free Ca2+.

The calcium-sensitive photoprotein aequorin has been used to measure cytoplasmic free Ca in single rat ventricle myocytes during metabolic inhibition. Rounding-up of the myocytes, and blebbing of the surface, occurred while free Ca remained at normal resting levels of 1 to 3 X 10(-7)M. Control over free Ca is less susceptible to metabolic blockade than is structural organization.