[An analysis of the antihypertensive properties of 3-nitropropionic acid, a compound from plants in the genus Astragalus].
3-Nitropropionic acid (NPA), a compound obtained from Astragalus species, elicited a dose-dependent relaxation of precontracted rabbit aortic rings. The remotion of endothelium or the presence of atropine, propranolol or brompheniramine did not modify the vasodilator effect of NPA but methylene blue clearly inhibited it. On the other hand the acute i.v. administration of NPA in normotensive rats or the chronic oral administration of NPA in renal hypertensive dogs, provoked both a decrease in blood pressure and bradycardia. Finally, NPA elicited negative inotropic and chronotropic effects in guinea pig isolated auricles, which were not blocked by atropine and it inhibited the increase in contractile force and heart rate elicited by isoproterenol. The present results indicate that NPA has vasodilator and antihypertensive properties. The arterial relaxation elicited by NPA was inhibited with methylene blue suggesting that it is a consequence of guanylate cyclase stimulation. The hypotensive effect was independent of the animal species or route of administration used. The bradycardia seen in rats and dogs and the negative chronotropic and inotropic effects observed in isolated auricles suggest that the hypotensive effect of NPA is a mixture of vasodilator and cardiodepressor actions. NPA cardiac effects may be related with inhibition of beta-adrenergic mediated responses.
Castillo
C
C
Departamento de Fisiología y Farmacología de la Escuela Superior de Medicina del I.P.N. Plan de San Luis y Díaz Mirón, Casco de Santo Tomás, México, D.F.
Valencia
I
I
Reyes
G
G
Hong
E
E
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001011:Aorta / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004730:Endothelium, Vascular / Q000187:drug effects; D005260:Female; D006168:Guinea Pigs; D006977:Hypertension, Renal / Q000188:drug therapy / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D009574:Nitro Compounds; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D011422:Propionates / Q000494:pharmacology / Q000627:therapeutic use*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar
D000959:Antihypertensive Agents; D009574:Nitro Compounds; D010936:Plant Extracts; D011422:Propionates; C015392:3-nitropropionic acid
Análisis de las propiedades antihipertensivas del ácido-3-nitropropiónico, un compuesto proveniente de plantas del género Astragalus.