[Pharmacological analysis on the mode of action of mandelamidine, a long-acting hypotensive agent (1). Comparison with guanethidine].
MA produced a temporary and long lasting hypotension in anesthetized animals. MA like guanethindine caused relaxation of the nictitating membrane in unanesthetized cats and inhibited the contraction of the nictitating membrane elicited by electrical stimulation at various frequencies of preganglionic cervical sympathetic nerve in anesthetized cats. The mode of neuron blocking action of MA differed from guanethidine on the contraction of the nictitating membrane elicited by stimulation at high frequencies. Neuron blocking action of MA was also shown on rat inferior eyelid, dog carotid occlusion, rabbit jejunum and guinea-pig vas deferens. Moreover that of MA like guanethidine on the cat nictitating membrane was reversed by a following administration of methamphetamine. MA slightly potentiated the effects of norepinephrine, epinephrine and reduced the effects of tyramine on the responses of the cat nictitating membrane and blood pressure, but did not potentiate the effects of norepinephrine on the guinea-pig vas deferens and rabbit pulmonary artery. MA produced a contraction of the cat nictitating membrane and this contraction was inhibited by pretreatment with reserpine or phentolamine. However, MA did not produce a rise in blood pressure in spinal cats nor did it reduce the contractile force and heart rate in guinea-pig atria. These findings suggest that sympathomimetic action and uptake inhibition of the catecholamine of MA was weaker than that of guanethidine.
D000578:Amidines / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000378:metabolism; D002415:Cats; D004149:Dioxoles / Q000494:pharmacology*; D004285:Dogs; D005143:Eyelids / Q000187:drug effects; D005260:Female; D006145:Guanethidine / Q000494:pharmacology*; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D007583:Jejunum / Q000187:drug effects; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D009541:Nictitating Membrane / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D014649:Vas Deferens / Q000187:drug effects
D000578:Amidines; D000959:Antihypertensive Agents; D002395:Catecholamines; D004149:Dioxoles; D008694:Methamphetamine; D006145:Guanethidine