Quantification of XXXX paradox in neonatal @entity35 hearts.

@entity141 @entity35 @entity10943 @entity460
Many indexes of damage have been used to quantify the @entity460 ( @entity141 ) paradox. We report here how different conclusions may be reached concerning the severity of the paradox when different indexes of damage are used. Hearts from 3- to 24-day-old and adult @entity35 were isolated, depleted of @entity141 for 5 min, and then @entity141 repleted. @entity10943 loss, @entity141 gain, and ultrastructural changes were monitored. Our results indicate that with increasing age each of these parameters shows a progression toward the adult state. However, this progression does not proceed at the same rate for each parameter. There was very little release of @entity10943 from hearts of @entity35 of less than 11 days old, but the amount released increased with increasing age. There appeared to be a direct relationship between the amount of @entity10943 released and the proportion of extremely contracted cells with disrupted sarcolemma. However, hearts from @entity35 of all ages gained @entity141 , suggesting that @entity141 entry occurs via contracture-dependent and contracture-independent routes. Thus we are able to dissociate @entity141 gain from the development of contracted cells and @entity10943 release at the youngest ages. Different conclusions could therefore be reached as to the severity of the @entity141 paradox at these youngest ages depending on which indexes of damage are documented.
