Induction of dark-adaptive retinomotor movement (cell elongation) in teleost retinal cones by cyclic adenosine 3','5-monophosphate.
Induction of dark-adaptive retinomotor movement (cell elongation) in teleost retinal cones by cyclic adenosine 3','5-monophosphate.
复制标题
通过环状腺苷3'，'5-磷酸磷酸盐诱导黑暗视网膜锥体中暗体自适应视网膜运动运动（细胞伸长）。
DOI：
10.1085/jgp.79.5.759
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发表时间：
1982-05
影响因子：
3.8
通讯作者：
Chader, G J
中科院分区：
文献类型：
--
作者：
Burnside, B;Evans, M;Fletcher, R T;Chader, G J
在硬骨鱼视网膜中，光感受器和视网膜色素上皮（RPE）响应于光条件的变化和内源性昼夜节律而经历广泛的运动（称为视网膜运动）。光感受器的运动用于重新定位光感受外节，并受到内节长度变化的影响。RPE细胞内的黑色素颗粒运动为视杆细胞外节提供了可移动的黑色素屏障。在黑暗中（夜晚），视锥细胞伸长，视杆细胞收缩，色素颗粒聚集到RPE细胞的基部;在光照下（白天），这些运动被逆转。我们在此报道，升高细胞质环腺苷酸（cAMP）的治疗引起视网膜运动，这是夜间暗适应的特征，即使在中午的强光下也是如此。为了说明这种反应，我们提出了一个定量的描述环核苷酸锥长度的影响，在绿色太阳鱼，蓝太阳鱼。当光适应性视网膜暴露于伴有磷酸二酯酶（PDE）抑制剂的外源性cAMP类似物（通过眼内注射或在视网膜器官培养中）时，诱导视锥伸长。视锥细胞运动不受环GMP类似物的影响。剂量反应研究表明，视锥伸长的程度，但不是速率，是成比例的外源性cAMP和类似物的浓度。正如已经报道的其他物种，我们发现，cAMP的水平显着高于黑暗-比光适应绿色翻车鱼视网膜。根据这些观察，我们认为cAMP在光和昼夜调节硬骨鱼锥长度中起作用。
In the teleost retina, the photoreceptors and retinal pigment epithelium (RPE) undergo extensive movements (called retinomotor movements) in response to changes in light conditions and to an endogenous circadian rhythm. Photoreceptor movements serve to reposition the light-receptive outer segments and are effected by changes in inner segment length. Melanin granule movements within the RPE cells provide a movable melanin screen for rod outer segments. In the dark (night), cones elongate, rods contract, and pigment granules aggregate to the base of the RPE cell; in the light (day), these movements are reversed. We report here that treatments that elevate cytoplasmic cyclic adenosine 3',5'-monophosphate (cAMP) provoke retinomotor movements characteristic of nighttime dark adaptation, even in bright light at midday. To illustrate this response, we present a quantitative description of the effects of cyclic nucleotides on cone length in the green sunfish, Lepomis cyanellus. Cone elongation is induced when light-adapted retinas are exposed to exogenous cAMP analogues accompanied by phosphodiesterase (PDE) inhibitors (either by intraocular injection or in retinal organ culture). Cone movements is not affected by cyclic GMP analogies. Dose-response studies indicate that the extent, but not the rate, of cone elongation is proportional to the concentration of exogenous cAMP and analogue presented. As has been reported for other species, we find that levels of cAMP are significantly higher in dark- than in light-adapted green sunfish retinas. On the basis of these observations, we suggest that cAMP plays a role in the light and circadian regulation of teleost cone length.