Biochemistry Classroom Research Articles

Arginase is an enzyme that nephrologists can love

In this issue of the journal, Demougeot et al. [1] report that arginase inhibition enhances endothelial function and attenuates high blood pressure development in spontaneously hypertensive rats (SHR). The word arginase conjured up ancient memories in my mind of dusty biochemistry classrooms and lectures from all too long ago. I recalled having learned that arginine is a semiessential amino acid required during periods of maximal growth, severe stress, and injury. Arginine is not only a substrate for protein synthesis, but also modulates cellular biochemical functions via conversion to a number of biologically active compounds. Arginine is utilized by a vast variety of metabolic pathways that produce many regulatory compounds, such as nitric oxide, creatine phosphate, agmatine, polyamines, ornithine and citrulline. Arginine supplies are primarily regulated by two enzyme systems. The enzymes are arginase, which is part of the urea cycle, and nitric oxide synthase, which produces NO.