Effect of ammonium acetate on the somatostatinergic system in the rat frontoparietal cortex.
Short (90 min)-, mid (5 days)-, and long-term (15 days) ammonium acetate (5 mmol/kg IP) administration decreased the number of specific [125I][Tyr11]somatostatin receptors in synaptosomes from the frontoparietal cortex without changing the affinity constant. Administration of ammonium acetate did no affect the levels of somatostatin-like immunoreactivity in the frontoparietal cortex. The administration of a single dose of N-carbamyl-L-glutamate (1 mmol/kg) plus L-arginine (1 mmol/kg) 1 h before the last administration of ammonium acetate totally blocked the inhibitory effects of the latter on somatostatin receptor number in the frontoparietal cortex synaptosomes. N-Carbamyl-L-glutamate plus L-arginine alone had no observable effect on the somatostatinergic system. The decrease in the number of somatostatin receptors induced by ammonium acetate might reflect decreased target cell sensitivity to somatostatin, a phenomenon that could contribute to the depressed neuronal excitability induced by ammonia in the rat frontoparietal cortex.
Boyano
M C
MC
Department of Biochemistry and Molecular Biology, Medical School, University of Alcalá, Madrid, Spain.
Bodega
G
G
Arilla
E
E
D000085:Acetates / Q000008:administration & dosage*; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D005625:Frontal Lobe / Q000187:drug effects* / Q000378:metabolism; D005971:Glutamates / Q000494:pharmacology; D008297:Male; D010296:Parietal Lobe / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017481:Receptors, Somatostatin / Q000187:drug effects* / Q000378:metabolism; D013004:Somatostatin / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism
D000085:Acetates; D005971:Glutamates; D017481:Receptors, Somatostatin; C006895:N-carbamylglutamate; D013004:Somatostatin; D001120:Arginine; C018824:ammonium acetate