Jeffrey P L
Pharmacol Biochem Behav. 1976 Nov;5(5):571-5. doi: 10.1016/0091-3057(76)90271-9.
Earlier investigations of sympathomimetic drugs overcoming the amnesic action of cycloheximide (CXM) in day-old chickens were extended to biochemical studies in vitro. The effects of amphetamine, norepinephrine, alpha and beta noradrenergic stimulants and receptor blockers on Na+/K+ ATP'ase activity in total homogenate of chicken forebrain were investigated. Norepinephrine and the beta stimulant, isoprenaline significantly stimulated the activity of this enzyme, while the beta blocker, propranolol inhibited activity. Amphetamine, the alpha stimulant, methoxamine and the alpha receptor blocker, piperoxane had no effect on Na/K+ ATP'ase activity in total homogenate. In a purified synaptosomal preparation, both amphetamine (5 X 10(-5) M) and norepinephrine (1 X 10(-4) M) produced a slight stimulation of Na+/K+ ATP'ase activity. A similar concentration of amphetamine (1.12 X 10(-4) M) did not inhibit 14C-leucine uptake or incorporation into protein in the synaptosomal fraction. Nor was it able to alleviate CXM inhibition of 14C-leucine incorporation into synaptosomal protein. The results are interpreted in terms of amphetamine (via release of norepinephrine) norepinephrine and isoprenaline stimulating and maintaining the labile, sodium pump-dependent, phase of memory formation for a sufficient length of time until protein synthesis inhibition by CXM wears off.
早期对拟交感神经药物克服环己酰亚胺（CXM）对一日龄雏鸡失忆作用的研究扩展到了体外生化研究。研究了苯丙胺、去甲肾上腺素、α和β去甲肾上腺素能兴奋剂及受体阻滞剂对鸡前脑全匀浆中Na⁺/K⁺ ATP酶活性的影响。去甲肾上腺素和β兴奋剂异丙肾上腺素显著刺激了该酶的活性，而β阻滞剂普萘洛尔则抑制了活性。苯丙胺、α兴奋剂甲氧明和α受体阻滞剂哌氧环烷对全匀浆中的Na⁺/K⁺ ATP酶活性没有影响。在纯化的突触体制剂中，苯丙胺（5×10⁻⁵ M）和去甲肾上腺素（1×10⁻⁴ M）均对Na⁺/K⁺ ATP酶活性产生了轻微刺激。类似浓度的苯丙胺（1.12×10⁻⁴ M）并未抑制突触体部分中¹⁴C-亮氨酸的摄取或掺入蛋白质中。它也无法减轻CXM对¹⁴C-亮氨酸掺入突触体蛋白质的抑制作用。这些结果的解释是，苯丙胺（通过释放去甲肾上腺素）、去甲肾上腺素和异丙肾上腺素刺激并维持记忆形成中不稳定的、依赖钠泵的阶段足够长的时间，直到CXM对蛋白质合成的抑制作用消失。
