[Comparative analysis of the effect of endogenous antibiotic defensin NP-1 and aminoglycoside antibiotic gentamicin on synaptic transmission in receptors of the frog vestibular apparatus].
The effect of human and rabbit neutrophilic defensins NP-1 and amonoglycoside antibiotic gentamicin on the synaptic transmission in the afferent synapse of isolated vestibular apparatus of the frog has been comparatively studied. Both defensins proved active in the concentration range of 0.0001 to 1 nM and efficiently decreased the impulse frequency in the afferent nerve fibers in a concentration-dependent manner. No significant differences in the efficiency of rabbit and human defensin NP-1 have been revealed in these experiments. Gentamicin also had an inhibitory effect on the afferent discharge in the concentration range of 10-500 microM (0.5-25 mg/kg). The inhibitory effect of gentamicin on the impulse activity of the vestibular nerve was observed at therapeutic doses. The excitatory effect of the putative neurotransmitter L-glutamate was considerably inhibited by defensin NP-1. These findings suggest that the mechanism of defensin action involves a modification of the synaptic transmission the hair receptor and is mediated by L-glutamate.
Andrianov
Iu N
IuN
Nozdrachev
A D
AD
Ryzhova
I V
IV
D000344:Afferent Pathways / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005839:Gentamicins / Q000494:pharmacology*; D018698:Glutamic Acid / Q000378:metabolism / Q000494:pharmacology; D018069:Hair Cells, Vestibular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D011817:Rabbits; D011896:Rana temporaria; D017470:Receptors, Glutamate / Q000378:metabolism*; D012665:Semicircular Canals / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D014725:Vestibular Nerve / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D023084:alpha-Defensins / Q000302:isolation & purification / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D017470:Receptors, Glutamate; D023084:alpha-Defensins; C406564:defensin NP-1; D018698:Glutamic Acid