Abstract
Adult cats adapted to a semi-purified casein diet were used to study the effects of chronic doses of gluten or gliadin administered per os for 16 consecutive days, for a total of 700mg per kg per day, on various blood and brain parameters. The ad libitum food intake, serum amino acid content, brain, adrenal, and serum dopamine-β-hydroxylase activity, and cerebral GABAergic, cholinergic, dopaminergic, noradrenergic, and serotonergic metabolism of cats fed casein gluten or gliadin were studied. In the brain, the wheat proteins favored mesolimbic and nigrostriatal dopaminergic pathways and decreased the choline acetyltransferase and glutamic acid decarboxylase activities in these pathways thus suggesting an interaction between the corresponding neurotransmitters. The decreased food intake in cats fed gluten or gliadin was paralleled by an increased noradrenaline, dopamine, and serotonin contents in the brainstem areas. In treated cats the adrenal and serum dopamine-β-hydroxylase activities were decreased whereas this enzyme activity in the brain remained normal. The ratio of serum total tryptophan or tyrosine to the sum of six neutral amino acids were significantly decreased and inversely correlated with serotonin and catecholamine contents in the brain. Biochemical peripheral and cerebral disturbances observed following chronic gluten or gliadin administration could provide some basis for correlated behavioral properties of wheat peptides.
