儿茶酚胺对鱼视网膜水平细胞膜电位的影响。

Effects of catecholamines on the horizontal cell membrane potential in the fish retina.

作者信息

Negishi K, Drujan B D

出版信息

Sens Processes. 1978 Dec;2(4):388-95.

Abstract

The effects of catecholamines (CA) and certain related compounds on the horizontal cell membrane potential were examined in the retina of the teleost (Eugerres plumieri). Each CA compound (dopamine, noradrenaline, and adrenaline) had a similar effect on each class of horizontal cell (photopic L- and C-type, scotopic L-type). The threshold effect, seen with 25-50 microM CA, was an enlargement of both center and surround responses in general. At higher concentrations (100-200 microM), CA augmented the center response and attenuated the surround considerably; these reciprocal changes usually were associated with moderate depolarization. Recovery took place in 15-20 min. The results indicate that up to a certain concentration CA do not affect directly the transmission from photoreceptors to horizontal cells. The lateral propagation of S-potential, however, appears selectively affected by CA. alpha-Methylnoradrenaline, 5-hydroxydopamine, and serotonin caused the same effect on horizontal cells as CA. Reserpine, clonidine, and L-dopa mimic the CA effect only after prior application of CA. Phentolamine blocked while propranolol, haloperidol, and pimozide did not influence the DA effect. We conclude that alpha-adrenergic receptors probably are involved in the CA-induced changes observed in horizontal cells.

摘要

在硬骨鱼（Eugerres plumieri）的视网膜中，研究了儿茶酚胺（CA）和某些相关化合物对水平细胞膜电位的影响。每种CA化合物（多巴胺、去甲肾上腺素和肾上腺素）对每一类水平细胞（明视L型和C型、暗视L型）都有相似的作用。25 - 50微摩尔CA产生的阈值效应通常是中心和周边反应都增大。在较高浓度（100 - 200微摩尔）时，CA增强中心反应并显著减弱周边反应；这些相反的变化通常与适度的去极化有关。恢复在15 - 20分钟内发生。结果表明，在一定浓度范围内，CA不会直接影响从光感受器到水平细胞的信号传递。然而，S电位的横向传播似乎受到CA的选择性影响。α - 甲基去甲肾上腺素、5 - 羟基多巴胺和血清素对水平细胞的作用与CA相同。利血平、可乐定和左旋多巴仅在预先应用CA后才模拟CA的作用。酚妥拉明可阻断而普萘洛尔、氟哌啶醇和匹莫齐特不影响多巴胺的作用。我们得出结论，α - 肾上腺素能受体可能参与了在水平细胞中观察到的CA诱导的变化。