Structural and functional modifications induced by ketamine on synaptosomes in the rat.
This study correlates previous observations on the effects of a general anaesthetic (2-chlorophenyl-2-methylaminocyclohexanone, trade name Ketalar), administered in vivo on the functional properties of synaptosomes from the brain of the rat, with structural modifications detected using freeze-fracture electron microscopy. The anaesthetized rats exhibited a fluidization of the synaptic membranes, as probed by stearic acid spin labels, accompanied by a decrease in the activity of acetylcholinesterase. The freeze-fracture images of synaptosomes from anaesthetized rats showed a clear statistical increase in the number of vesicles with aggregated intramembrane particles, without any significant change of the particle diameter. The hypothesis that a perturbation of the lipid protein interaction is a primary effect, in the mechanism of action of anaesthetics, is supported at present only by indirect evidence.
Mazzanti
L
L
Instituto di Biochimica, School of Medicine, Ancona, Italy.
Lenaz
G
G
Marinelli
F
F
Cinti
S
S
D000110:Acetylcholinesterase / Q000378:metabolism; D000758:Anesthesia; D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D005614:Freeze Fracturing; D066298:In Vitro Techniques; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013113:Spin Labels; D013570:Synaptic Membranes / Q000187:drug effects / Q000201:enzymology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure
D013113:Spin Labels; D007649:Ketamine; D000110:Acetylcholinesterase