Effect of Ribonuclease on the Ribonucleic Acid, Adenosine Triphosphate and Catecholamine Content of Medullary Granules

Abstract

IN a previous communication¹ we have shown that incubation with ribonuclease or trypsin at 37° C caused a dose-dependent release of catecholamines and ATP from, medullary granules of cattle. The trypsin-induced release is probably due to its proteolytic action, since the protein content of the granules is also considerably diminished. Ribonuclease, on the contrary, does not release protein; it liberates only catecholamines and ATP. We therefore suggested that ribonucleic acid may play an important part in the storage of catecholamines and ATP in the granules. This communication describes the ribonucleic acid content of chromaffin granules and its relationship to the content of catecholamines and ATP as well as the influence of ribonuclease on these three components.