Attenuated development of hypertension by chronic administration of bromocriptine in Doca-salt hypertensive rats

The aim of the study was to investigate whether or not the development of hypertension is influenced by chronic treatment with bromocriptine and/or domperidone. Rats treated with DOCA-salt were divided into 4 groups: control with vehicle, bromocriptine, bromocriptine with domperidone, and domperidone. Increased blood pressure by DOCA-salt treatment was significantly suppressed by treatment with bromocriptine and this bromocriptine suppression was significantly blocked by treatment with domperidone. Increased urinary excretion of norepinephrine by DOCA-salt treatment was significantly suppressed by bromocriptine and the inhibiting effect of bromocriptine disappeared with domperidone. In the four groups of rats, there were significant correlations between systolic blood pressure and urinary excretion of norepinephrine, systolic blood pressure and urinary excretion of epinephrine, and urinary excretion of dopamine and sodium. These results suggest that the chronic effect of bromocriptine is to suppress development of DOCA-salt hypertension, mainly through peripheral mechanisms which are involved in the decreased release of norepinephrine.