title: No effect of atrial natriuretic factor on cardiac rate, force and transmitter release.
abstract: The effects of atrial natriuretic factor (ANF, 1-300 nmol/l) on cardiac rate, force and neurotransmitter release were examined in guinea-pig isolated heart preparations. Synthetic ANF had little effect on the contractile force of electrically driven papillary muscle regardless of the presence or absence of isoprenaline. The pulse period of spontaneously beating right atria was not affected by ANF. Neither the positive nor negative chronotropic effect of isoprenaline or bethanechol respectively were changed in the presence of ANF. ANF did not affect the release of neurotransmitter from the nerve endings in the isolated atrium. ANF was confirmed to relax isolated aortic rings precontracted with either noradrenaline (ANF,IC50 = 3 nmol/l,s.e.m. = 0.2, n = 5) or potassium (ANF,IC50 = 24 nmol/l, s.e.m. = 0.2, n = 5). These results demonstrate that ANF within doses effective for vasorelaxation has no appreciable effect on myocardial function or neutrotransmitter release in the heart.
authors.forename: M
authors.initials: M
authors.lastname: Hiwatari
authors.forename: K
authors.initials: K
authors.lastname: Satoh
authors.forename: J A
authors.initials: JA
authors.lastname: Angus
authors.forename: C I
authors.initials: CI
authors.lastname: Johnston
mesh_terms: D000320:Adrenergic Fibers / Q000378:metabolism; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002799:Cholinergic Fibers / Q000378:metabolism; D006168:Guinea Pigs; D006321:Heart / Q000294:innervation*; D006325:Heart Atria; D006339:Heart Rate / Q000187:drug effects*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010210:Papillary Muscles / Q000187:drug effects; D011984:Sensory Receptor Cells / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D009320:Atrial Natriuretic Factor