Urinary excretion of kallikrein following myocardial infarction.

Kinin has been hypothesized to be involved in the mechanism of the procordialgia, collapse, and shock in myocardial infarction. In spontaneous and experimental animal infarction, the long-lasting lowering of plasma kininogen is perhaps the expression of kinin release from the plasma precursor. More recently, a durable reduction of plasma prekallikrein and of the plasma inhibitor of kallikrein, both evaluated with the kaolin contact method, has been demonstrated to support the implication of the kinin system in the course of myocardial infarction. In the present study, the dialy urinary excretion of kallikrein, according to the Porcelli and Croxatto method, has been studied in a group of patients with acute myocardial infarction and in a group of control patients, Differences between the two groups have been observed. They consist mainly in strong daily oscillations in the amount of urinary kallikrein excretion during the 24 hour period in the group of patients with myocardial infaction. At this moment, however, it is not possible to give a definite interpretation of these results.