Adrenal catecholamine concentration after chronic treatment with bromocriptine and haloperidol

Adrenal catecholamine concentration was measured by HPLC with electrochemical detection in male rats after ten days of bromocriptine and haloperidol (0.05, 0.5 and 5.0 mg kg-1) and vehicle (1.0 ml kg-1) treatments subcutaneously. There were four rats in each group. The results indicate that bromocriptine treatment significantly increased dopamine (DA), noradrenaline (NA) and adrenaline (A) content in a dose-dependent manner. The NA/DA ratio was unchanged, but the A/NA ratio was significantly increased after treatments with two higher doses of the drug. Haloperidol treatment, on the other hand, had no significant effect on dopamine and a biphasic effect on adrenaline content. Noradrenaline concentration increased only after the lowest dose of the drug. There was no significant change in NA/DA or A/NA ratios in any group. The dopamine metabolite, dihydroxyphenylacetic acid (DOPAC), was not detected in any adrenal gland.