Summary
Inotropic responses were measured in isolated rat left atria using an isometric force transducer. In atria from adult rats tyramine administration or field stimulation of intramural cardiac nerves (in the presence of atropine) caused a positive inotropic response which was as great as that obtainable with exogenous noradrenaline. In contrast, atria from newborn animals showed very poor inotropic responses to nerve stimulation or tyramine although they already responded well to noradrenaline. The responses developed progressively with age, reaching adult levels at 3 to 4 weeks of age. It is concluded that the postnatal development of myocardial sympathetic nerves is correlated with a development of the positive inotropic response to sympathetic nerve stimulation or to tyramine.
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References
Atwood, G.F. & Kirshner, N. (1976). Postnatal development of catecholamine uptake and storage of the newborn rat heart. Develop. Biol.49, 532–538.
Bennett, T. & Malmfors, R. (1974). Regeneration of the noradrenergic innervation of the cardiovascular system of the chick following treatment with 6-hydroxydopamine. J. Physiol. Lond.242, 517–532.
Blackshaw, S. & Warner, A. (1976). Onset of acetylcholine sensitivity and endplate activity in developing myotome muscles ofXenopus. Nature262, 217–218.
Blinks, J.R. (1966). Field stimulation as a means of effecting the graded release of autonomic transmitters in isolated heart muscle. J. Pharmac. exp. Ther.151, 221–235.
Chubb, I.W., De Potter, W.P. & De Schaepdryver, A.F. (1972). Tyramine does not release noradrenaline from splenic nerve by exocytosis. Naunyn-Schmiedebergs Arch. Pharmac. 274, 281–286.
Crout, J.R., Muskus, A.J. & Trendelenburg, U. (1962). Effect of tyramine on isolated guineapig atria in relation to their noradrenaline stores. Br. J. Pharmac.18, 600–611.
De Champlain, J., Olson, L., Malmfors, T. & Sachs, C. (1970). Fluorescent morphology of developing peripheral adrenergic nerves in the rat. Acta physiol. scand.80, 276–288.
Iversen, L.L., De Champlain, J., Glowinski, J. & Axelrod, J. (1967). Uptake, storage and metabolism of norepinephrine in tissues of the developing rat. J. Pharmac. exp. Ther.157, 509–516.
Mackenzie, E. & Standen, N.B. (1976). Adrenergic innervation of the mouse heart revealed at an early stage using α-methylnoradrenaline. Cell Tiss. Res.173, 129–132.
Owman, C., Sjoberg, N-O. & Swedin, G. (1971). Histochemical and chemical studies on pre- and post-natal development of the different systems of ‘short’ and ‘long’ adrenergic neurons in peripheral organs of the rat. Z. Zellforsch.116, 319–341.
Sachs, C., De Champlain, J., Malmfors, T. & Olson, L. (1970). The postnatal development of noradrenaline uptake in the adrenergic nerves of different tissues from the rat. Eur. J. Pharmac.9, 67–79.
Thoa, N.B., Wooten, G.F., Axelrod, J. & Kopin, I.J. (1975). On the mechanism of release of norepinephrine from sympathetic nerves induced by depolarising agents and sympathomimetic drugs. Mol. Pharmac.11, 10–18.
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Standen, N.B. Postnatal development of inotropic responses to nerve stimulation and tyramine in rat atria. Pflugers Arch. 370, 99–101 (1977). https://doi.org/10.1007/BF00707953
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DOI: https://doi.org/10.1007/BF00707953