Cycloheximide

Cycloheximide is an antibiotic that inhibits protein synthesis at the translation level, acting exclusively on cytoplasmic (80s) ribosomes of eukaryotes. Cycloheximide affected all the energy-dependent stages in the protein-synthesizing process. However, the initiation seems the most sensitive. Cycloheximide also affects respiration, ion uptake, amino acid biosynthesis, and DNA and RNA synthesis, effects that are probably secondary to its effect on protein synthesis.^[1]

In vitro study indicated that Cycloheximide at 1 μM inhibited [3H]leucine incorporation into both cellular and secreted proteins by at least 86%, without having deleterious effects on membrane integrity as indicated by trypan blue uptake and lactate dehydrogenase release. Larger size class polysomes (7⁺) were increased by Cycloheximide treatment and remained increased during recovery. ^[2]

In vivo analysis indicated that Cycloheximide produced initial hyperactivity. This initial hyperactivity was apparent within 3 minutes after injection of the Cycloheximide. Cycloheximide affects activity by acting on the brain, and this is unrelated to its inhibition of protein synthesis. In addition, Cycloheximide’s effects on activity did not appear to be responsible for its amnesic action. However, Cycloheximide might have some other property, unrelated to inhibition of cerebral protein synthesis, that is responsible for its amnesic effect.^[3]

References:
[1]. Marcos R, et al. Effect of Cycloheximide on different stages of Drosophila melanogaster. Toxicol Lett. 1982 Sep;13(1-2):105-12.
[2].Helinek TG, et al. Initial inhibition and recovery of protein synthesis in cycloheximide-treated hepatocytes. Biochem Pharmacol. 1982 Apr 1;31(7):1219-25.
[3]. Segal DS, et al. Cycloheximide: its effects on activity are dissociable from its effects on memory. Science. 1971 Apr 2;172(3978):82-4.

环己酰亚胺是一种抗生素，它在翻译水平上抑制蛋白质合成，仅对真核细胞的细胞质（80s）核糖体起作用。环己酰亚胺影响蛋白质合成过程中所有依赖能量的阶段，但启动似乎最为敏感。环己酰亚胺还会影响呼吸、离子摄取、氨基酸生物合成以及DNA和RNA合成等效应，这些效应可能是由其对蛋白质合成的影响所致。^[1]

体外研究表明，1微米的环丝氨酸甲基转移酶（Cycloheximide）至少抑制了86％的[3H]亮氨酸蛋白质合成，而不会对细胞膜完整性产生有害影响，这是通过尝试蓝染色和乳酸脱氢酶释放来确定的。大型多聚体（7+）在环丝氨酸甲基转移酶处理后增加，并在恢复期间保持增加。

在体内分析表明，环丝氨酸霉素会产生初始的过度活跃。这种初始的过度活跃在注射环丝氨酸霉素后3分钟内就能显现出来。环丝氨酸霉素通过作用于大脑影响活动，而这与其抑制蛋白质合成无关。此外，环丝氨酸霉素对活动的影响似乎不是导致其遗忘作用的原因。然而，环丝氨酸霉素可能具有一些其他性质，与抑制大脑蛋白质合成无关，这些性质可能是导致其遗忘效应的原因。^[3]