THE URINARY EXCRETION OF A DEPRESSOR SUBSTANCE (KALLIKREIN OF FREY AND KRAUT) IN ARTERIAL HYPERTENSION

While the explanation of the immediate mechanism causing persistent elevation of blood pressure has in recent years been greatly clarified in terms of increased arteriolar resistance, the underlying factors, with certain exceptions, which regulate arteriolar tonus are not clearly defined. Maintenance of normal blood pressure, together with adequate tissue nourishment, demands a nice physiologic adjustment between cardiac output, circulating blood volume and available vascular bed. Such adjustment conceivably may be mediated through nervous, chemical or hormonal influences acting either singly or in consonance. As regards their influence upon arteriolar tonus, while something is known of the regulatory activities of the nervous system, the possible importance of the chemical and hormonal influences remains obscure and offers a fertile field for investigation. It is probable that the ultimate answer to the question of arterial hypertension will be found in this field, and a large amount of both experimental...