Phlorizin, a competitive inhibitor of glucose transport, facilitates memory storage in mice.
Posttraining intraperitoneal administration of phlorizin (3.0-300.0 microg/kg), a competitive inhibitor of glucose transport from blood to brain, facilitated 48-h retention, in male Swiss mice, of a one-trial step-through inhibitory avoidance task. The dose-response curve was an inverted-U shape. Phlorizin did not increase the retention latencies of mice that had not received a foot shock during training. The effects of phlorizin (30.0 microg/kg) on retention were time dependent, and the administration of phlorizin (30.0 microg/kg) 5 or 10 min prior to the retention test did not affect the retention performance of mice given posttraining injections of saline or phlorizin (30.0 microg/kg). These findings indicate that phlorizin influenced memory storage, but not memory retrieval. Finally, the simultaneous administration of phlorizin (3. 0-300.0 microg/kg, ip) antagonized, in a dose-related manner, the memory impairment induced by insulin (8 IU/kg, ip). Taken together, the results show that phlorizin enhance retention acting as a "glucose-like substance" although the mechanism(s) of this enhancement is unknown.
Boccia
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MM
Cátedra de Farmacología-Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Junín 956-5 degrees Piso, 1113-, Argentina.
Kopf
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SR
Baratti
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CM
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D007328:Insulin / Q000494:pharmacology; D008297:Male; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000037:antagonists & inhibitors*; D010695:Phlorhizin / Q000494:pharmacology*; D012153:Retention, Psychology / Q000187:drug effects*
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D010695:Phlorhizin