辣椒素简介

体外细胞培养实验中，激活大鼠背根神经节细胞膜上的VR1可观察到单片钙离子的涌入。这个过程包括细胞内钙的快速增加(几分钟)和钙浓度的恢复(几十分钟)。与通过钾去极化在同一细胞中激活电压门控钙通道相比，VR1激活引起细胞内钙浓度增加的幅度和速度相似，但钙恢复到静止水平的速度要慢得多。很多。对线粒体解耦剂的研究发现，线粒体在这一过程中作为细胞内钙离子的缓冲剂。当细胞外钙离子大量涌入时，线粒体吸收钠离子和钙离子。当细胞质中的钙离子恢复时，线粒体会释放钙离子，从而延长恢复时间。在这个漫长的恢复过程中，神经细胞对细胞外钾和辣椒素都没有反应。这可能与辣椒素的脱敏作用和对疼痛的记忆有关。人工克隆表达的VR1可被香兰素化合物、氢离子、大于43℃的热和pH≤5.9的酸激活。 Therefore, some people think that VR1 is a molecular complex that causes pain caused by chemical and physical stimuli. There are also experimental results that do not support this hypothesis. Nagy et al. compared the cell membrane responses of rat primary sensory cells to capsaicin pepper and noxious thermal stimuli using electrophysiological and ion current measurement methods, and confirmed that there are many similarities in the properties of ion channels activated by capsaicin pepper or thermal stimuli. , but there is also an important difference, that is, the permeability of calcium ions in heat-activated channels is lower than that of capsaicin pepper-activated channels. Channels that respond to heat stimuli or capsaicin pepper are monosensitive, and only a few ion channels have dual sensitivity to heat and capsaicin pepper. At the whole cell level, each cell can respond to heat or capsaicin pepper. Therefore, it is inferred that capsaicin pepper is substantially different from the molecules that induce cellular responses to thermal stimulation, and may be related to multiple isoforms of VR1.