Copper Content and Exchange in Mammalian Hearts

¹ University of Chicago, Pritzker School of Medicine, 950 East 59th Street, Chicago, Illinois 60637

Determination of the copper (Cu) content of rat, rabbit, and mouse hearts proved to be a sensitive microassay for mitochondrial content and membrane area of mitochondrial cristae per unit myocardial cell volume. The direction of variations in Cu content correlated well with variations in membrane area of mitochondrial cristae determined by morphometry of electron micrographs during normal postnatal growth, ventricular hypertrophy after aortic constriction, and thyroxin-stimulated myocardial cell growth. Right and left ventricular and interventricular septal Cu contents per unit dry weight were the same, did not vary during postnatal growth, and significantly exceeded atrial Cu content. Among different mammalian species, ventricular Cu content per unit dry weight tended to vary inversely with adult animal size and thus with adult resting heart rate. The existence of mechanisms for transport of ⁶⁷Cu across the myocardial cell plasma membrane and for incorporation of ⁶⁷Cu into mitochondrial cristae from an intracellular precursor pool was demonstrated by injecting ⁶⁷Cu-labeled blood serum into rats.

Submitted on October 10, 1973
Accepted on March 21, 1974