Szabó G, Kovács G L, Baláspiri L, Telegdy G
Acta Physiol Hung. 1983;62(1):25-33.
Prolyl-leucyl-glycinamide (PLG) and its substituted and protected analogues were tested on the steady-state level of noradrenaline (NA), dopamine (DA) and serotonin (5-HT) in various brain areas. The tripeptides were structurally modified at the N-terminal proline residue either by protection with benzoxycarbonyl (Z group) or by tertiary butyroxycarbonyl (BOC), or by substitution with homoproline (HPRO). C-terminal modification was performed by substitution of the amino group of glycine (GLY-NH2) by methylester (GLY-OMe). The parent molecule (PLG) increased the 5-HT content in the striatum and the NA and DA levels in the dorsal hippocampus. N-terminal protection by Z-group resulted in a loss of these effects. Striatal effects re-appeared if a methylester group was introduced in the C-terminal glycine. Substitution of the N-terminal with HPRO or that of the C-terminal amine group by OMe resulted in a tendency to increase the 5-HT level in the hypothalamus.
对脯氨酰 - 亮氨酰 - 甘氨酰胺（PLG）及其取代和保护类似物在不同脑区去甲肾上腺素（NA）、多巴胺（DA）和5 - 羟色胺（5 - HT）的稳态水平上进行了测试。这些三肽在N端脯氨酸残基处进行了结构修饰，方法包括用苄氧羰基（Z基团）保护、叔丁氧羰基（BOC）保护或用高脯氨酸（HPRO）取代。C端修饰是通过用甲酯（GLY - OMe）取代甘氨酸的氨基（GLY - NH₂）来进行的。母体分子（PLG）增加了纹状体中的5 - HT含量以及背侧海马体中的NA和DA水平。Z基团进行的N端保护导致这些效应消失。如果在C端甘氨酸中引入甲酯基团，纹状体效应会再次出现。用HPRO取代N端或用OMe取代C端胺基会导致下丘脑5 - HT水平有升高的趋势。
