1. The effects of systemic, intrastriatal or intranigral administration of d-amphetamine on glutamate, aspartate, ascorbic acid (AA), uric acid, dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in dialysates from the striatum of freely-moving rats were evaluated using microdialysis. 2. d-Amphetamine (2 mg kg-1) given subcutaneously (s.c.) increased DA, AA and uric acid and decreased DOPAC + HVA, glutamate and aspartate dialysate concentrations over a 3 h period after d-amphetamine. 5-HIAA concentrations were unaffected. Individual changes in glutamate and AA dialysate concentrations were negatively correlated. 3. d-Amphetamine (0.2 mM), given intrastriatally, increased DA and decreased DOPAC + HVA and aspartate dialysate concentrations, but failed to change those of glutamate, AA uric acid or 5-HIAA, over a 2 h period after d-amphetamine. Haloperidol (0.1 mM), given intrastriatally, increased aspartate concentrations without affecting those of glutamate or AA. 4. d-Amphetamine (0.2 mM), given intranigrally, increased AA and uric acid dialysate concentrations and decreased those of glutamate, aspartate and DA; DOPAC + HVA and 5-HIAA concentrations were unaffected. 5. These results suggest that d-amphetamine-induced increases in AA and uric acid and decreases in glutamate concentrations are triggered at nigral sites. The changes in aspartate levels may be evoked by at least two mechanisms: striatal (mediated by inhibitory dopaminergic receptors) and nigral (activation of amino acid carrier-mediated uptake).
On the mechanism of d-amphetamine-induced changes in glutamate, ascorbic acid and uric acid release in the striatum of freely moving rats / Miele, M; Mura, Ma; Enrico, Paolo; Esposito, G; Serra, Pier Andrea; Migheli, Rossana; Zangani, D; Miele, E; Desole, Maria Speranza. - In: BRITISH JOURNAL OF PHARMACOLOGY. - ISSN 1476-5381. - 129:3(2000), pp. 582-588.
On the mechanism of d-amphetamine-induced changes in glutamate, ascorbic acid and uric acid release in the striatum of freely moving rats.
ENRICO, Paolo;SERRA, Pier Andrea;MIGHELI, Rossana;DESOLE, Maria Speranza
2000-01-01
Abstract
1. The effects of systemic, intrastriatal or intranigral administration of d-amphetamine on glutamate, aspartate, ascorbic acid (AA), uric acid, dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in dialysates from the striatum of freely-moving rats were evaluated using microdialysis. 2. d-Amphetamine (2 mg kg-1) given subcutaneously (s.c.) increased DA, AA and uric acid and decreased DOPAC + HVA, glutamate and aspartate dialysate concentrations over a 3 h period after d-amphetamine. 5-HIAA concentrations were unaffected. Individual changes in glutamate and AA dialysate concentrations were negatively correlated. 3. d-Amphetamine (0.2 mM), given intrastriatally, increased DA and decreased DOPAC + HVA and aspartate dialysate concentrations, but failed to change those of glutamate, AA uric acid or 5-HIAA, over a 2 h period after d-amphetamine. Haloperidol (0.1 mM), given intrastriatally, increased aspartate concentrations without affecting those of glutamate or AA. 4. d-Amphetamine (0.2 mM), given intranigrally, increased AA and uric acid dialysate concentrations and decreased those of glutamate, aspartate and DA; DOPAC + HVA and 5-HIAA concentrations were unaffected. 5. These results suggest that d-amphetamine-induced increases in AA and uric acid and decreases in glutamate concentrations are triggered at nigral sites. The changes in aspartate levels may be evoked by at least two mechanisms: striatal (mediated by inhibitory dopaminergic receptors) and nigral (activation of amino acid carrier-mediated uptake).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.