Levels of dopamine, 5-hydroxytryptamine and their metabolites in the striatum of rats of various strains receiving a high-calorie diet

The aim of this work was to study the effect of a high fat and carbohydrate diet (HFCD) and quercetin supplementation on the levels of dopamine (DA), serotonin (5-HT) and their metabolites in Wistar, DA transporter knockout (DAT-KO) and obese Zucker fa/fa rats. Animals received a control diet or HFCD for 62 days. Wistar and Zucker fa/fa rats received quercetin. The contents of DA, 5-HT, norepinephrine (NE), dioxyphenyl acetate (DOPAC), homovanillic acid (HVA) and 5-hydroxyindolyl acetate (5-HIIA) in the striatum were determined by high-performance liquid chromatography (HPLC). DAT-KO homozygotes had lowered DA and increased HVA and DOPAC compared to Wistar rats. HFCD did not affect the content of NE and 5-HT. 5-HT was increased in DAT-KO homozygotes compared with Wistar receiving a control diet. 5-HIIA accumulated in larger amounts in DAT-KO compared to Wistar with the exception of those receiving quercetin with a control diet. Quercetin did not affect the levels of DA, 5-HT and their metabolites.