Frolov D.S., Sibarov D.A., Vol'nova A.B.
Altered spontaneous electric activity detected in rat motor neocortex
after intranasal epitalon infusions.
Proceedings of the 8th Conference "Stress & Behavior"
(May 17-19, 2004, St.Petersburg). In Psichofarmakol. Biol. Narkol. V.4.,
2004, N.2-3., P.724.
An
investigation of synthetic peptide epitalon (Ala-Glu-Asp-Gly) has been
performed. This class of peptides (epitalon, cortagen, livagen,…) is
known to protect the organism against different stress factors like
osmotic stress, radiation, tumor growth et al, while the mechanisms
of their action remain unclear Epitalon has been constructed on the
basis of epithalamin - pineal peptide extract - aminoacid analysis.
Intranasal infusion of epitalon solution used in this study seems to
be the most effective way to deliver peptide substance to CNS bypassing
blood-brain barrier.
Epitalon physiological activity was evaluated according to spontaneous
electric activity of rat frontal neocortex. Tiopental-anaesthetised
Wistar male rats (60 mg/kg body weight, i.p.) were fixed in stereotaxic
frame in screened and grounded camera. Extracellular electric activity
was recorded using glass microelectrode (1-2 MOhm). Spontaneous electric
activity has been recorded for 10 minutes before and up to 30 minutes
after intranasal epitalon inufusion. Epitalon caused significant (2-2,5
times) increase in action potentials frequency on the 5-th minute after
infusion. This delay between epitalon application and it’s physiological
action probably reflects the time of it’s transport from nasal cavity
to brain circulation. Multiple rhythmic firing of the cortical neurons
was sometimes accompanied with spontaneous movements of experimental
animal even under anaesthesia. It seems to be the result of epitalon
physiological action. This effect disappeared in 20-30 minutes after
the infusion.
This results suggest epitalon to successfully bypass blood-brain barrier
and to modulate motor cortical neuronal activity.