[Kinetics of Semax penetration into the brain and blood of rats after its intranasal administration].
Shevchenko. K V KV; Nagaev. I Iu IIu; Alfeeva. L Iu LIu; Andreeva. L A LA; Kamenskiĭ. A A AA; Levitskaia. N G NG; Shevchenko. V P VP; Grivennikov. I A IA; Miasoedov. N F NF
Key Findings
- Semax reaches the rat brain as fast as 2 minutes after intranasal administration
- Only ~0.093% of the total dose per gram of brain tissue is detected, indicating low overall penetration
- About 80% of the detected radioactivity is intact Semax, but it is rapidly degraded, mainly to the tripeptide Pro‑Gly‑Pro
Practical Outcomes
- Intranasal Semax can get into the brain quickly, but the amount is very small and it degrades fast, so users may need higher or repeated doses to see effects. The findings highlight the need for optimized dosing schedules or delivery methods for any human self‑experiments.
Summary
A rat study shows that spraying Semax into the nose gets the peptide into the brain within a couple of minutes, but only a tiny amount (about 0.1% of the dose per gram of brain tissue) makes it there, and most of it breaks down quickly into a small fragment. This suggests intranasal delivery works, but the drug’s short lifespan may limit its effectiveness without frequent dosing or special formulations.
Abstract
The radioactive peptide analogue Semax corresponding to the ACTH(4-10) sequence (Met-Glu-His-Phe-Pro-Gly-Pro) with a molar radioactivity of 56 Ci/mmol labeled with tritium at the C-terminal Pro was prepared. The labeled peptide was used for studying the kinetics of Semax penetration into rat brain and blood after its intranasal administration (50 microg/kg, 20 microl of solution) to nonbred white rats of body mass 200-250 g. It was demonstrated that 0.093% of the total introduced radioactivity per gram can be found in the rat brain 2 min after the administration, 80% of this radioactivity belonged to Semax, and the rest, to its metabolites. The peptide undergoes rapid enzymatic degradation, with the tripeptide Pro-Gly-Pro prevailing in biological samples relative to the total content of Semax and its metabolites.
Study Information
pubmed
2006
10.1134/s1068162006010055