Differences in high-energy phosphate catabolism between the rat and the dog in a heart preservation model.

Concentrations of ATP and creatine phosphate were measured in rat and dog hearts preserved either by cold storage (procedure A) or by continuous hypothermic perfusion (procedure B). In procedure A (3 dogs, 4 rats) the hearts were normothermically excised without cardioplegia and were stored in 0.9% NaCl at 0.5 degrees C; in procedure B (6 dogs, 21 rats) hypothermic cardioplegic arrest was performed, and then the hearts were retrogradely perfused through the aorta for 24 hours with use of an oxygenated Bretschneider cardioplegic solution at 2 degrees to 4 degrees C. Whole rat hearts were frozen using Wollenberger clamps at desired times during the preservation period; transmural needle biopsy specimens were sampled from dog hearts. In control nonpreserved hearts, the ATP and creatine phosphate were as follows (mean +/- SD): 26.7 +/- 4.1 and 27.1 +/- 10.3 mumol/gm dry weight, respectively (dog hearts), and 23.1 +/- 2.1 and 34.2 +/- 12.1 mumol/gm dry weight, respectively (rat hearts). With procedure A, ATP decreased by 36% in dog hearts and by 64% in rat hearts during the first hour of storage. By 24 hours, only 6% of the ATP remained in the dog hearts and 1% in the rat hearts. Creatine phosphate decreased by 85% (dog hearts) and by 93% (rat hearts) during the first hour of storage. The ATP and creatine phosphate values observed in rat hearts after 1 hour of procedure A preservation were significantly lower than in dog hearts (p less than 0.05). With procedure B, cardioplegic arrest by itself did not alter high-energy phosphate concentrations in dog or rat hearts.(ABSTRACT TRUNCATED AT 250 WORDS)