Renin-Angiotensin System: Plasma Versus Tissues

摘要: The classical view of the renin-angiotensin system (RAS) as an endocrine system, designed to deliver its active end-product, angiotensin II, tissues via circulating blood, has been challenged in past two decades by studies demonstrating high tissue levels well release I from sites. II could not be explained on basis diffusion and/or receptor-mediated uptake thereby supporting concept that is largely, if completely, synthesized locally. Remarkably, many organs (in particular heart and vessel wall) this local synthesis depends (i.e. kidney-derived) renin prorenin, either into interstitial space or through binding (pro)renin receptors. Renin prorenin receptors located cell membrane, combined with fact angiotensin-converting enzyme (ACE) also a membrane-associated enzyme, favours generation surface. Although demonstrated intracellularly, intracellular unlikely occur, due lack angiotensinogen internalization. Tissue further supported clinical RAS blockade, ACE inhibitors receptor antagonists, results beneficial cardiac, vascular renal effects are independent, at least part, blood pressure-lowering these drugs. Taken together therefore, generated sites, where it acts paracrine autocrine hormone, blockers exert their mainly interference II.