title: Alpha-human atrial natriuretic peptide is a coronary vasodilator in the Langendorff-perfused guinea pig heart.
abstract: The circulating form of atrial natriuretic peptide is now believed to be composed of 28 amino acids (1). Therefore, we studied the coronary vasoactivity of the 28 amino acid, alpha-human atrial natriuretic peptide (alpha-hANP) in five isolated guinea pig hearts Langendorff-perfused at constant pressure (46 mmHg) with Krebs-Henseleit solution. The reactivity of the coronary bed was assured in each heart with bolus injections of norepinephrine, adenosine, and the vasoconstrictor atrial natriuretic peptide, atriopeptin II (APII). APII was a coronary constrictor in each of these five hearts. Nineteen boluses of alpha-hANP were administered to the five hearts, spanning the range 1.6 to 64 nmol/g wet heart weight. alpha-hANP was vasodilator in all five hearts. The equation for the regression of y = flow, % increase, on x = dose, nmol/g, is y = 17.98 logx - 4.11. The correlation coefficient, r, is 0.83, and the coefficient of determination, r2, is 0.69. Analysis of variance of the regression of y on x yields an F statistic of 36.9, P less than 0.00001. These results indicate that coronary vasodilation is correlated with dose of alpha-hANP over much of the range 1.6-64 nmol/g.
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D009320:Atrial Natriuretic Factor