Effect of 6-hydroxydopamine and thyroxine on chronotropic response to norepinephrine

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Abstract

Rats were pretreated with 6-hydroxydopamine (6-OH-DA), thyroxine (T4 or a combination of 6-OH-DA and T4. At the end of the treatment period, the hearts were removed and perfused by the Langendorff technique; heart rate was recorded and the chronotropic response to various doses of norepinephrine was measured. Histochemical examination for catecholamine-containing nerves was performed on hearts from each group of animals. It was found that 6-OH-DA, but not T4, produced an increase in sensitivity of the heart to norepinephrine. Hearts from rats treated with 6-OH-DA, but not T4, were markedly depleted of adrenergic nerve terminals. It was concluded that chemical sympathectomy induced by 6-OH-DA caused the heart to be hypersensitive to norepinephrine and that 6-OH-DA was capable of producing marked depletion of sympathetic fibers in the myocardium.

References (15)

  • W.R. Brewster et al.

    The hemodynamic and metabolic interrelationships in the activity of epinephrine, norepinephrine and the thyroid hormones

    Circulation

    (1956)
  • B. Falck

    Observations on the possibilities of the cellular localization of monoamines by a fluorescence method

    Acta Physiol. Scand.

    (1962)
  • B. Falck et al.

    Fluorescence of catecholamines and related compounds condensed with formaldehyde

    J. Histochem. Cytochem.

    (1962)
  • M.J. Goodkind

    The influence of thyroid hormone on myocardial metabolism of norepinephrine in the guinea-pig

    J. Pharmacol. Exptl. Therap.

    (1966)
  • G. Haüsler et al.

    Chemische Sympathektomie der Katze mit 6-Hydroxydopamin: Veränderungen von Sympathicusreizeffekten und Noradrenalinempfindlichkeit

    Helv. Physiol. Pharmacol. Acta

    (1968)
  • J. Leduc et al.

    Distribution of adrenaline and noradrenaline in the normal and hyperthyroid rat following adrenaline administration

    Can. J. Biochem. Physiol.

    (1955)
  • W.H. MacMillan et al.

    The effects in rabbits of thyroidectomy and treatment with triiodothyronineon the sensitivity to noradrenaline and the content of noradrednaline in aorta and spleen

    J. Pharmacol., (London)

    (1962)
There are more references available in the full text version of this article.

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This work was supported by grants from the National Institutes of Health, U.S. Public Health Service (1 R01 NB-06707-04, HE-01813 and DE-02623) and from a Grant-in-Aid from the American Heart Association.

∗∗

Riker International Fellow of IUPHAR. Present address: Dept. of Pharmacology, School of Medicine, Zabrze 8, Poland.

∗∗

Public Health Service Research Career Development Award from the NAtional Institutes of Health, K3-GM-3504 (M.E.H.) and 5-K3-NB-13935-03 (D.J.).

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