Effect of intraperitoneal acetyl-L-carnitine (ALCAR) on anxiety-like behaviours in rats.
Acetyl-L-carnitine (ALCAR) is an acetyl derivative of carnitine, an endogenous molecule synthesized in vivo and supplemented by diet (mainly via meat and dairy products). Several parallel, double-blind, placebo-controlled studies have demonstrated that ALCAR treatment produces beneficial effects in geriatric depression. Since most antidepressants also have anti-anxiety effects we examined whether ALCAR shows anti-anxiety effects in a rat model of anxiety. Compared to a saline-injected control group, chronic administration of ALCAR at doses of 10 and 100 mg/kg (tested 24 h after the last dose administration) showed no effects, whereas doses of 50 and 75 mg/kg significantly reduced anxiety-like behaviours in the elevated plus-maze. Acute ALCAR (100 mg/kg), on the other hand (tested 6 h after administration), demonstrated anxiogenic effects. Our data suggest that chronic ALCAR administration may produce an inverted U-shaped curve of dose-dependent changes in anxiety-like behaviour. The precise mechanism by which ALCAR decreases anxiety-like behaviour after peripheral administration remains to be determined.
Levine
Joseph
J
Ministry of Health Mental Health Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Kaplan
Zeev
Z
Pettegrew
Jay W
JW
McClure
Richard J
RJ
Gershon
Samuel
S
Buriakovsky
Igor
I
Cohen
Hagit
H
D000108:Acetylcarnitine / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D014151:Anti-Anxiety Agents / Q000627:therapeutic use*; D001007:Anxiety / Q000139:chemically induced / Q000188:drug therapy* / Q000523:psychology; D001143:Arousal / Q000187:drug effects*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004353:Drug Evaluation, Preclinical; D005106:Exploratory Behavior / Q000187:drug effects; D005239:Fear / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D014151:Anti-Anxiety Agents; D000108:Acetylcarnitine