Renin-Synthesizing Cells in the Kidney and Beyond

The benefit of Renin-Angiotensin System (RAS) blockade in cardiovascular and renal disease is undisputed, but what is still controversial is the optimal degree of RAS blockade. A high degree of RAS blockade may have additional beneficial effects, but also results in a higher incidence of side effects. The degree of blockade can be estimated from the increase in circulating renin, depicting the “recruitment” of new renin-producing cells (RPC) along the afferent arterioles. The long-term consequences of this process are still unknown, nor do we know if it contributes to renal impairment in the future. Besides renin production, RPC would participate directly in the concentric vascular hypertrophy, despite the control of the blood pressure levels.
This thesis focuses on the RPCs, their current knowledge, novel aspects, and a new approach to understand these cells biology. Furthermore, we have analyzed the concept of extrarenal sites of renin production, and the (pro)renin reabsorption in the proximal tubule. Our data support the Juxtaglomerular cells, in the kidney, as only source of renin in the body, on which angiotensin generation depends. The complete understanding of the RPCs “recruitment” and its further consequences, combined with a full comprehension of local (renal) angiotensin production will ultimately allow more effective anti-hypertensive therapies, and better outcomes in patients with cardiovascular and renal pathologies.