Hernandez D E, Simons K B, Spampinato D, Rioux F, St-Pierre S
Neuropeptides. 1985 Dec;6(6):561-8. doi: 10.1016/0143-4179(85)90119-2.
We have previously reported that intracameral (I.C.) administration of neurotensin (NT) potently induces a time- and dose-dependent miosis in rabbits. This study was designed to determine structure-function relationships for NT-induced miosis. NT and twelve different fragments and analogs of NT, and the structurally-unrelated peptides beta-endorphin (beta-end), somatostatin (SRIF) and thyrotropin-releasing hormone (TRH) were tested in a dose equimolar to 30 micrograms of NT for their effects on pupillary diameter (PD) in rabbits. In confirmation of previous findings, NT produced significant miosis. Followed in order of duration of effect were D-Trp11-NT, D-Tyr11-NT, the N-terminal fragment NT1-12, [Gln4] - NT and NMe-NT. The N-terminal fragment NT1-8, D-Arg8-NT, and D-Phe11-NT were weakly active. In addition, the initial N-terminal fragment NT1-6 and the C-terminal fragments NT8-13 and NT9-13 did not affect PD. D-Pro10-NT, beta-end, SRIF, and TRH were totally ineffective. The results of this investigation contribute to support a role for NT on regulation of pupillary function, and suggest that the midportion of NT appears to be critical for the expression of NT-induced miosis.
我们之前曾报道，前房内（I.C.）注射神经降压素（NT）可在兔中有效诱导出时间和剂量依赖性的瞳孔缩小。本研究旨在确定NT诱导瞳孔缩小的结构-功能关系。用与30微克NT等摩尔剂量的NT及其十二个不同的片段和类似物，以及结构不相关的肽β-内啡肽（β-end）、生长抑素（SRIF）和促甲状腺激素释放激素（TRH），来测试它们对兔瞳孔直径（PD）的影响。正如之前的研究结果所证实的，NT可产生显著的瞳孔缩小。按作用持续时间排序依次为D-Trp11-NT、D-Tyr11-NT、N端片段NT1-12、[Gln4]-NT和NMe-NT。N端片段NT1-8、D-Arg8-NT和D-Phe11-NT活性较弱。此外，最初的N端片段NT1-6以及C端片段NT8-13和NT9-13对PD没有影响。D-Pro10-NT、β-end、SRIF和TRH完全无效。本研究结果有助于支持NT在调节瞳孔功能中的作用，并表明NT的中间部分似乎对NT诱导瞳孔缩小的表达至关重要。
