Jumblatt J E
Department of Ophthalmology, University of Louisville School of Medicine, KY 40202.
Neurosci Lett. 1988 Jun 7;88(3):286-90. doi: 10.1016/0304-3940(88)90225-x.
The effects of several representative calcium channel antagonists on depolarization-evoked release of [3H]-norepinephrine were investigated in isolated, superfused rabbit iris-ciliary bodies. Potassium (50 mM)-evoked neurosecretion was blocked by 5 mM CoCl2 and partially inhibited by 10(-6) M nitrendipine or verapamil. Electrically-evoked neurosecretion was similarly blocked by CoCl2, but was unaffected by nitrendipine or verapamil. It is concluded from these results that sympathetic terminals in the rabbit iris-ciliary body contain dihydropyridine- and verapamil-sensitive calcium channels which contribute, under conditions of prolonged depolarization, to neurotransmitter release.
在离体、灌流的兔虹膜睫状体中，研究了几种代表性钙通道拮抗剂对去极化诱发的[3H] - 去甲肾上腺素释放的影响。5 mM 氯化钴可阻断钾（50 mM）诱发的神经分泌，10(-6) M 尼群地平或维拉帕米可部分抑制该过程。氯化钴同样可阻断电诱发的神经分泌，但尼群地平或维拉帕米对其无影响。从这些结果得出结论，兔虹膜睫状体中的交感神经末梢含有对二氢吡啶和维拉帕米敏感的钙通道，在长时间去极化条件下，这些通道有助于神经递质的释放。
