Pharmacological Action of FD-008, a New Dopamine Beta-hydroxylase Inhibitor. I. Effects on Blood Pressure in Rats and Dogs

Hypotensive action of a new dopamine beta-hydroxylase (DBH) inhibitor, 5-(4'-chlorobutyl)picolinic acid (FD-008) was investigated in dogs and rats. FD-008, which is one of the most potent inhibitors among fusaric acid derivatives, decreased blood pressure in spontaneously hypertensive rats relatively parallel to DBH inhibition in vitro. The effect of FD-008 on blood pressure was stronger in hypertensive rats than in normotensive rats. No cumulative effect was observed in rats by repeated administration, On the other hand, repeated administration was required to lower blood pressure in normotensive dogs. The acute effect of FD-008 on blood pressure of anesthetized dogs was somewhat different from that of its mother compound, fusaric acid.