(1) It is probably that tolazoline also releases acetylcholine from the guinea pig atria.
(2) Exposure of rabbit atria to theophylline, 2.5 X 10(-4) M, did not potentiate the inotropic effects of tolbutamide.
(3) At higher concentrations of burimamide, inhibition curves showed distinct evidence of departure from competitive character for both guinea pig and rabbit atria.
(4) At a concentration of 10 microM, tetraamine 4 did not affect histamine and 5-hydroxytryptamine receptors of guinea pig ileum or alpha-adrenoreceptors of guinea pig atria whereas it inhibited postsynaptic alpha-adrenoreceptors of rat vas deferens with a -log K value of 5.23 and nicotinic receptors of frog rectus abdominis with an IC50 value of 0.23 microM.
(5) Isoprenaline produced positive chronotropic responses in right atria and positive inotropic responses in left atria and ventricular strips.
(6) In both the atria and the ventricles of adult SHR, [125I]351A binding was very significantly reduced.
(7) The heart atria represent the major site of synthesis for atrial natriuretic peptide (ANP) which exerts potent natriuretic, diuretic and vasoactive functions.
(8) In a noncontracting in vitro preparation of combined right and left atria we demonstrated by electron microscopy that, at 37 degrees C, transition from zero pressure to a physiological distending pressure of 5.1 mm Hg rapidly rendered atrial endocardial endothelium permeable to the macromolecular probes horseradish peroxidase (HRP; M(r), approximately 40,000) and wheat germ agglutinin-HRP (M(r), approximately 70,000); each probe was introduced at the atrial cavitary endocardial surface.
(9) There was no statistically significant difference in basal concentrations of immunoreactive atrial natriuretic peptide (ANP), as assessed by radioimmunoassay, between right and left atrial muscle of control rats; similarly, stereological analysis showed no statistically significant difference in the fractional volume of myocytes occupied by specific heart granules, or in numerical density of granules, between right and left atria.
(10) In the CS, myocarditis with fibrosis was found in all in the approaches to the sinoatrial (SA) node, the SA node, the atria, the atrioventricular (AV) node, and the bundle and bundle branches, to a varying degree.
(11) Spontaneously beating right atria increased ANP secretion by 2.3-fold in response to 10 nM endothelin without a change in beat frequency.
(12) Both compounds were less potent than isoprenaline in increasing either the rate of beating of isolated right atria or the contractile force of left atria, OPC-2009 being 4 and 127 times and salbutamol being 100 and 700 times less potent on the respective preparations.
(13) Although all of the primary particulate fractions exhibited binding activities, the bulk of the total homogenate binding activity was associated with the washed particles sedimenting at the lower gravitational forces; this was observed with either atria or ventricles of dog, guinea pig, rabbit, hamster, and rat.
(14) Furthermore, the long axis of the right and left atria was measured from the center of the apposed atrioventricular valve leaflets to the posterior atrial wall, and the sizes of the atrial chambers were defined using their widths at the prospective broadest points through the area of foramen ovale.
(15) 1 The positive inotropic and chronotropic responses to sympathomimetic amines were examined in guinea-pig isolated atria.
(16) These alterations highly resembled that triggered by spleen lymphocytes from autoimmune myocarditis mice, when they reacted with normal atria.
(17) The isolated atria from mice hyperimmunized with heart exhibited tachycardia, decrease in contractility and dysrhythmia.
(18) Implantation of multiple stimulating and recording electrodes allowed wavelength determination at four different areas: the right and left parts of Bachmann's bundle and the free walls of the right and left atria.
(19) In vitro, the spontaneously beating atria were significantly suppressed by dehydroevodiamine in a dose-dependent manner.
(20) The atria were studied at a pacing frequency of 0 or 3 Hz.
Atrip
Definition:
(adv.) Just hove clear of the ground; -- said of the anchor.
(adv.) Sheeted home, hoisted taut up and ready for trimming; -- said of sails.
(adv.) Hoisted up and ready to be swayed across; -- said of yards.