Bevan J A
Blood Vessels. 1978;15(1-3):17-25. doi: 10.1159/000158149.
The frequency response curves (FRC) of isolated blood vessels differ from each other not only in their initial slopes, but in their maxima, and their intercept on the frequency axis. Within the physiological range, there is a linear relation between response and frequency. The FRC of most vessels with junctional innervation are similar, varying only somewhat with innervation density. Other factors found to influence the FRC are: variation in innervation distribution, in the extent of myogenic propragation, and large differences in the sensitivity of the alpha-adrenergic receptor. The effectiveness of the transmitter increases with frequency rise. The maximum effective radius of the transmitter released from one varicosity is only several microns. In vessels with light to moderate innervation density at low frequencies, there is probably little overlap of transmitter effect from adjacent varicosities even at the outermost layers of smooth muscle cells. There is a disparity between neurogenic response and that which might be expected from the direct action of the transmitter. It is proposed that a local limited myogenic extension of excitation may extend the local action of a quantum of transmitter.
离体血管的频率响应曲线（FRC）彼此不同，不仅在于其初始斜率，还在于其最大值以及在频率轴上的截距。在生理范围内，响应与频率之间存在线性关系。大多数具有接头神经支配的血管的FRC相似，仅随神经支配密度略有变化。发现影响FRC的其他因素有：神经支配分布的变化、肌源性传播程度的变化以及α-肾上腺素能受体敏感性的巨大差异。递质的有效性随频率升高而增加。从一个曲张体释放的递质的最大有效半径仅为几微米。在低频下神经支配密度为轻度至中度的血管中，即使在平滑肌细胞的最外层，相邻曲张体的递质效应可能也几乎没有重叠。神经源性反应与递质直接作用所预期的反应之间存在差异。有人提出，兴奋的局部有限肌源性扩展可能会扩大一个量子递质的局部作用。
