NA-Selank Amidate is a chemically modified analogue of Selank, a synthetic tuftsin-derived heptapeptide, carrying an N-terminal acetyl group and a C-terminal amide; the published research base concerns the parent peptide Selank rather than the modified analogue itself.
Selank is a synthetic heptapeptide developed at the Institute of Molecular Genetics in Russia, built from the immunomodulatory tetrapeptide tuftsin (Thr-Lys-Pro-Arg) extended with a Pro-Gly-Pro stabilising sequence. NA-Selank Amidate is a further-modified analogue in which the N-terminus is acetylated and the C-terminus is amidated.
Terminal acetylation and amidation are standard peptide-chemistry strategies for reducing exopeptidase susceptibility, since they remove the free amine and free carboxylate that amino- and carboxypeptidases recognise. The same modification pattern is used in NA-Semax Amidate relative to Semax.
An important caveat for anyone using this entry: essentially all peer-reviewed pharmacology cited below was generated with Selank, not with the acetylated-amidated analogue. Direct comparative studies of NA-Selank Amidate are not established in the indexed literature, and the status is recorded here as limited research on that basis.
The Selank literature describes several reported mechanisms in rodent and cell models: modulation of GABA-A receptor-linked signalling and of gene expression relating to GABAergic neurotransmission, changes in monoamine turnover (including reported increases in the ratio of 5-hydroxyindoleacetic acid to serotonin in hypothalamus and striatum, interpreted as accelerated serotonin turnover), and effects on enkephalin-degrading enzyme activity in plasma.
Neurotrophic signalling is a second reported axis. Following intranasal administration in rats, investigators reported increases in hippocampal BDNF messenger RNA within roughly three hours and BDNF protein within about twenty-four hours, alongside differential expression of genes associated with neuronal plasticity and inflammation. Whether the acetylated and amidated analogue reproduces these findings has not been established in the published literature.
Intranasal Selank and hippocampal BDNF (rat). Species/model: adult rats. Route as studied: intranasal. Measure: hippocampal BDNF messenger RNA and protein, plus transcriptome-wide expression. Reported outcome: BDNF messenger RNA increased within approximately 3 hours and BDNF protein within approximately 24 hours after a single administration, with differential expression of genes linked to neuronal plasticity and inflammation [1][3].
GABAergic gene expression in cell culture. Model: IMR-32 human neuroblastoma cells. Measure: expression of genes involved in GABAergic neurotransmission, with GABA and olanzapine as comparators. Reported outcome: Selank altered expression of genes in this pathway in the reported conditions [2].
Rodent behavioural and neurochemical characterisation. Species/model: laboratory rodents. Measures: open-field activity, elevated plus maze, Morris water maze, and regional monoamine and metabolite concentrations. Reported outcome: an anxiolytic-type behavioural phenotype with increased 5-HIAA to serotonin ratios in hypothalamus and striatum, interpreted by the authors as accelerated serotonin turnover rather than raised absolute serotonin [3].
Evidence caveat. All four bodies of work above used Selank. No peer-reviewed head-to-head comparison of NA-Selank Amidate against Selank on these endpoints was located during compilation of this entry. Terminal-modification effects on potency, half-life and brain exposure should be treated as unresolved [4].
Combinations examined in the research literature. Descriptive only — not a recommendation to combine compounds.