PHOTOSENSITIVITY OF THE FROG IRIS.
PHOTOSENSITIVITY OF THE FROG IRIS.
复制标题
DOI：
10.1085/jgp.46.6.1249
复制
发表时间：
1963-07
影响因子：
3.8
通讯作者：
ALPERN, M
中科院分区：
文献类型：
--
作者：
BARR, L;ALPERN, M
视紫红质对量子的吸收导致蛙虹膜肌收缩。宫缩在光线下约8秒后达到最大。当光关闭时，虹膜会呈指数型弛缓，弛缓时间约为6秒。膜极化不是反应所必需的，但钙离子运动和膜通透性的变化可能是反应所必需的。这种反应不是由乙酰胆碱或肾上腺素介导的。当使用较大的响应标准时，恒定响应幅度的log It与log t的曲线在短时间内逐渐向上弯曲，远离单位斜线，因为(a)光在较长时间内影响张力发展，(b)高强度、短持续时间的闪光效果较差。
The absorption of quanta by rhodopsin leads to the contraction of frog iris muscle. The contractions reach a maximum after about 8 sec. in the light. When the light is turned off the irises relax exponentially with a half-time of about 6 sec. Membrane polarization is not necessary for the response but calcium movement and membrane permeability changes probably are. The response is not mediated by acetylcholine or epinephrine. The curves of log It vs. log t for constant response amplitude bend progressively upward away from a unit slope line at short times as larger response criteria are used because (a) light influences tension development over longer times and (b) the higher intensity, shorter duration flashes are less effective.