Activated and inactivated renin-angiotensin system in transgenic animals: from genes to blood pressure

Much of our knowledge about blood pressure regulation has come from a huge number of biochemical, endocrinologic, pharmacologic, clinical, and physiologic studies. The renin-angiotensin system, composed of enzymatic and signal-transduction cascades, has a key role in regulating arterial blood pressure and in developing certain forms of experimentally induced hypertension and hypertension in human beings. Angiotensin peptides, the products of this system, exert a wide range of physiologically important effects on many tissues, including those of the cardiovascular system, through their actions on angiotensin receptors. Recently, several groups have succeeded in generating animals transgenic for the renin or angiotensinogen genes, or with a targeted disruption of the component genes of the renin-angiotensin system. This brief review describes advances of the in vivo analysis of blood pressure regulation by focusing on the renin-angiotensin system.