Evidence for species differences between rats and gerbils in striatal dopamine content and dopamine metabolism

High-performance liquid chromatography revealed significantly higher striatal concentrations of dopamine and homovanillic acid (HVA) in 9 male Mongolian gerbils than in 6 male Long-Evans rats. 5-Hydroxyindoleacetic acid concentrations were higher in rats, while no significant between-species difference was found with respect to 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin or protein concentrations. In gerbils, HVA and DOPAC occurred in approximately equal concentrations, suggesting that the formation of HVA may be of greater significance for the termination of transmitter function in the gerbil than in the rat.