The renin system for long-term control over vasoconstriction and sodium-volume homeostasis in the spectrum of hypertension: three new frontiers in research.

This morning I have presented something old and something new and I have tried to point out what I think are some promising areas of current research. In the past two decades we have made great strides in our understanding of hypertensive mechanisms. We now know that essential hypertension can no longer be viewed an a single entity. Its heterogeneity in renin patterns is matched by heterogeneity in response or lack of response of individual patients to different types of drugs, and by heterogeneity in risk and prognosis. Analysis of renin system patterns has proven to be very productive for enabling us to understand the participation of the vasoconstriction or volume factors that inevitability work to maintain all hypertensive states. This bipolar analysis of hypertensive phenomena in turn has led to better diagnosis and to more specific treatment of individual patients. In our present state of knowledge, we still need to understand why the renin system so often inappropriately participates in maintenance or causation of the hypertensive state and why it fails to turn itself off in medium or high renin patients. In the low renin patients we do not understand why renal sodium retention occurs nor how it produces sustained increases in peripheral resistance. Three of many potentially exciting areas for expanding our knowledge are the prorenin problem, the natriuretic hormone problem, and the recently discovered relationships between the divalent cations, calcium and magnesium, and the concurrent renin system patterns in the renin subgroups of essential hypertension. Perhaps one of these areas will serve as an appetizer for the participants here today, and in particular for the man we honor, Franz Gross.