Conducted vasomotor responses in arterioles: characteristics, mechanisms and physiological significance

摘要: Micropipette application of certain vasoconstrictor or -dilator substances onto the surface arterioles induces both a local vasomotor response and which is propagated up- downstream along vessel, so-called conducted response. In some vascular beds dilator responses are detectable more than millimetre from site agonist delivery. While agonists such as acetylcholine, noradrenaline, KCl almost invariably give rise to others, sodium nitroprusside vasopressin, do not. Conducted in appear rely on passive electrotonic spread change membrane potential induced by at tip pipette. Presumably current spreads arteriolar wall through endothelial smooth muscle cell gap junctions. Whether electrical signal primarily layer currently not known, but it may depend used. Experiments have suggested that vasodilation skeletal feed plays an important role development functional hyperaemia onset exercise. kidney, vasoconstriction believed be responsible for upstream contraction afferent arteriole interlobular artery known occur activation macula densa. Therefore could tubuloglomerular feedback mechanism. Finally, experimental studies shown conduction altered pathological conditions associated with microvascular dysfunction arterial hypertension sepsis.