Spontaneous activity in the microvasculature of visceral organs: role of pericytes and voltage‐dependent Ca2+ channels

摘要: The microvasculature plays a primary role in the interchange of substances between tissues and circulation. In visceral organs that undergo considerable distension upon filling, appears to display intrinsic contractile properties maintain their flow. Submucosal venules bladder or gastrointestinal tract generate rhythmic spontaneous phasic constrictions associated Ca(2+) transients. These events are initiated within either venular pericytes smooth muscle cells (SMCs) arising from release sarcoplasmic reticulum (SR) opening -activated chloride channels (CaCCs) trigger influx through L-type voltage-dependent (VDCCs). VDCCs also play critical maintaining synchrony mural cells. stomach myenteric layer, transients originating capillary appear spread neighbouring arteriolar SMCs. Capillary primarily rely on SR release, but require T-type for synchrony. contribute propagation into microvasculature, act as spontaneously active machinery pacemaker generating synchronous drive contractions upstream arterioles. Thus different roles vascular beds manner may well depend selective expression channels.