Properties of mitochondria isolated from herring gull salt gland

¹ Johnson Research Foundation, University of Pennsylvania, Philadelphia, Pennsylvania

Mitochondria have been extracted from the salt gland of the herring gull (Larus argentatus) and were found to have normal relative amounts of cytochromes a₃, a, b, c, flavoprotein, and DPNH. The mitochondria exhibit respiratory control, energy-linked DPN reduction, and other properties in common with avian heart mitochondria. The amount of mitochondrial cytochrome c in the intact gland is estimated spectrophotometrically and found to be extremely high—43 µmoles/kg wet wt. The ADP utilization per cytochrome c per second at 37 C is 19. The efficiency of sodium transport is calculated to be 34/O₂ molecule or 8/ATP. This value is consistent with the thermodynamic limitations. Various possible mechanisms for sodium transport are considered in the light of these results.

Key Words: cytochromes • energy-linked DPN reduction • efficiency of sodium transport • Na/ATP values • P/O • redoxpump hypothesis • Na-K activated adenosine triphosphatase divalent cation pump of mitochondria

Submitted on July 15, 1963