Abstract
Antihypertensive activity of orally administered methyl O-(4-hydroxy-3-methoxycinnamoyl)reserpate (CD-3400) was examined and compared with such activity of reserpine and its related agents in conscious hypertensive rats. CD-3400, 4-16 mg/kg p.o., produced a marked antihypertensive effect lasting 6 hr and a slight decrease in heart rate in spontaneously hypertensive rats (SHR). Reserpine, 1-4 mg/kg, rescinnamine, 4-16 mg/kg, and syrosingopine, 8-32 mg kg p.o., produced effects similar to those of CD-3400. The order of antihypertensive activities of the agents was as follows: reserpine>CD-3400=rescinnamine>syrosingopine. In renal hypertensive rats and deoxycorticosterone hypertensive rats, CD-3400 and rescinnamine, 4-16 mg/kg, and reserpine, 1-4 mg/kg p.o., also produced an antihypertensive effect and the order of potency was as follows: reserpine>rescinnamine≥CD-3400. Repeated administrations of CD-3400, 2-12 mg/kg/day p.o., for 14 days, to SHR produced the marked constant antihypertensive effects during the administration period. The order of the potency was as follows: reserpine> rescinnamine>CD-3400. CD-3400 possessing a sustained antihypertensive activity may be prescribed in cases when long-term therapy is required for hypertensive patients.
