Pharmacological action of FD-008, a new dopamine-beta-hydroxylase inhibitor. III. Effects on endogenous biogenic amine levels in rats.

Effect of a new dopamine beta-hydroxylase inhibitor, 5-(4'-chlorobutyl)-picolinic acid (FD-008) on endogenous amine levels in various tissue of normotensive and spontaneously hypertensive rats were determined in comparison with its mother compound, fusaric acid, and disulfiram. FD-008 decreased norepinephrine (NE) levels in the brain and heart with a slight increase of dopamine (DA) level in the brain. NE lowering activity of FD-008 was stronger than that of fusaric acid. Disulfiram was less active and the activity was one-tenth of FD-008. FD-008 lowered NE level even when DA was increased by pretreatment with L-DOPA or iproniazid but did not cause a further significant reduction of NE when catecholamines were practically depleted by pretreatment with reserpine.