Effect of shosaikoto on plasma catecholamines

Plasma adrenaline (AD) and noradrenaline (NA) were determined using high performance liquid chromatography (HPLC) equipped with an electrochemical detector. In an experiment using non-treated adrenalectomized rats, most plasma AD appeared to originate from the adrenal medulla, while plasma NA came from other sites. When Shosaikoto, a Japanese and Chinese traditional medicinal mixture, was orally administered to rats, plasma AD levels decreased in a significant manner 60 min after treatment, while plasma NA levels were not changed. Pretreatment with pentobarbital inhibited the Shosaikoto-induced decrease of plasma AD levels.