The electrotonic architecture of the retinal microvasculature: modulation by angiotensin II

摘要: Non-technical summary  In the quest to understand how circulatory system adjusts microvascular function meet local metabolic demand, we focused on retina whose consists exclusively of microvessels. Since voltages induced by extracellular signals play a key role in generating vasomotor responses, characterized movement voltage within retinal microvasculature. To do this, quantified transmission between pairs recording pipettes located at well-defined sites capillary/arteriole plexuses freshly isolated from rat retina. We found that microvasculature is not simply homogeneous syncytium, but has complex electrotonic architecture with differing efficacies transmission. Furthermore, discovered static, modulated angiotensin. This newly appreciated action reveals vasoactive can alter functional organization and, thereby, regulate spatial extent system's response voltage-changing inputs. Abstract  The operational unit regulating perfusion demand. However, much remains be learned about this multicellular functionally organized. help address challenge, microvasculature, which particularly well adapted for decentralized control blood flow. study, perforated-patch sealed onto abluminal cells complexes adult These consisted capillaries, as tertiary and secondary arterioles. Dual experiments revealed spreading axially through capillary, arteriole or transmitted very efficiently decay rate only ∼5% per 100 μm. well-coupled syncytium since detected significant dissipation radial cell-to-endothelium also branch points capillary its Consistent capillaries being well-suited task transmitting signals, most efficient portion recordings angiotensin II potently inhibits axial As consequence, geographical microvasculature's inputs markedly restricted presence addition, effect established rather, dynamically signals.