Quinpirole (hydrochloride)

Quinpirole hydrochloride (LY 171555 hydrochloride) is a high-affinity agonist of dopamine D2/D3 receptor. IC50 & Target:Dopamine D2/D3 receptor^[1]. In Vivo: DA content is left brain biased across groups, and although this asymmetry appears greater in saline controls than all drug-treated groups, there is not a significant interaction between Side and Group. When each side is considered separately it can be seen that in the left brain structure, DA levels progressively decrease with chronic quinpirole treatment, with the QQ rats differing significantly from saline controls. In contrast, right cortical DA levels are only altered significantly (increased) by acute Quinpirole. It can be found that DOPAC levels are also left brain biased across groups. However, no significant Group or interaction effects are found. Rats receiving acute Quinpirole show a selective increase in DA content and decrease in turnover ratio, relative to either saline controls or the QS group. Sensitized (QQ) rats however, have elevated DOPAC levels in comparison to the acute quinpirole group. In striatum as well, all three measures of DA function differed significantly across groups (DA, F_3,33=6.27, P=0.0020; DOPAC, F_3,33=7.98, P=0.0004; turnover ratio, F_3,33=16.85, P<0.0001). In the acute quinpirole rats, both DOPAC and turnover ratio are significantly reduced relative to all other groups. In QQ rats, DOPAC levels are significantly greater than all other groups, while for turnover ratio, both chronic quinpirole groups were increased compared to both chronic saline groups^[1].