The way in which blood pressure is controlled is not well understood. I offer as evidence the spirited debates among scientists that have occurred in the past and that will probably continue for some time to come. Consider also that hypertension is a disease of significant morbidity and mortality, yet in the majority of instances the cause of the pressure elevation is unknown. And further, the wide variety of antihypertensive drugs currently used, often without a full understanding of the mechanisms involved, suggests that we often know as little about what decreases blood pressure with...