Brain monoamines and metabolites in hypertensive and hyperactive rat strains.

Monoamines and metabolites were measured by HPLC-EC in brain regions of four Wistar-Kyoto derived rat strains, in whom the traits of genetic hypertension or hyperactive behavior were expressed together (SHR), separately (WK-HT and WK-HA strains, respectively), or not at all (WKY). These genetically related inbred strains were used to allow more discrete correlations between neurochemical changes and the hypertensive and/or hyperactive state, than was hitherto possible using SHR and WKY metabolite levels were present in the six brain regions examined, however, no correlations with hypertension were observed. Limited correlations were seen between hyperactivity and forebrain serotonergic systems. These findings demonstrate that neurochemical differences between SHR and WKY may be erroneously attributed to the hypertension and/or hyperactivity of the SHR, unless additional genetic control strains, such as WK-HT and WK-HA rats are utilized.