Effects of Thyroid Hormone on Catecholamine and its Metabolite Concentrations in Rat Cardiac Muscle and Cerebral Cortex

Abstract

Clinical and experimental data suggest that thyroid hormone affects the actions of catecholamine (CA). However, the serum or tissue levels of CA during thyroid disorders have not been well defined. Accordingly, we investigated the levels of CA and their metabolites in the cardiac muscle, the cerebral cortex, and the plasma of rats with hyperthyroidism and hypothyroidism versus euthyroid animals. The Neurochem analyzer system (ESA, Inc., Bedford, MA) was used in such determinations. The cardiac muscles of hyperthyroid rats exhibited a 16% decrease in the levels of 1-dopa, 3-methoxytyramine (3-MT) and homovanillic acid (HVA) as compared with those in euthyroid rats. The levels of norepinephrine (NE) in cardiac muscle of these rats increased significantly (5.2-fold) relative to the levels in euthyroid rats. NE was undetectable in the cardiac muscles of the hypothyroid rats. Epinephrine (E) and dopamine (DA) were not detected in the cardiac muscles of the rats with either thyroid disorder. Levels of E and 3,4-dihydroxymandelic acid (DOPEG) were detected only in the cerebral cortex of hyperthyroid rats. The cerebral cortex levels of 3-methyoxytyramine (3-MT), 3,4-dihydroxyphenylacetic acid (DOPAC), metanephrine (MN), and homovanillic acid (HVA) were all significantly increased in the hyperthyroid versus the euthyroid rats. The cerebral cortex levels of DA, NE, normetanephrine (NMN), and VMA in the hyperthyroid rats all showed a significant decrease. Levels of NE, NMN, and DOPAC in the cerebral cortex increased significantly in the hypothyroid rats. The level of VMA was undetectable in cerebral cortex of such animals. Data from studies on cardiac muscle and cerebral cortex indicate that the changes in CA and CA metabolites are responsible in part for the cardiovascular and the central nervous system symptoms observed in hyperthyroidism and hypothyroidism.

Acute Effects of Triiodothyronine (T3) Replacement Therapy in Patients with Chronic Heart Failure and Low-T3Syndrome: A Randomized, Placebo-Controlled Study

“…This effect is mediated by promoting BNP gene transcription (22) or by regulating the rate of transcription of the ␤-1-adrenergic receptor gene (23). Accordingly, increased and decreased NT-proBNP levels have been observed in patients with hyperthyroidism or hypothyroidism, respectively (24), and parallel changes in the levels of catecholamine and catecholamine metabolites have been shown in cardiac muscle of rats with thyroid disorders (25). Similarly, decreased aldosterone circulating levels have been observed in hypothyroid patients treated with synthetic thyroid hormones (26).…”

Prevalence and Characteristics of Restless Legs Syndrome in Patients With Pulmonary Hypertension

“…20 The hypothyroid state has been associated with dopaminergic dysfunction in animal models 21 and abnormalities in catecholamine levels, 22 and patients with RLS are believed to have an impairment of the dopaminergic pathway. 4 In our study on lung transplant recipients, all 4 patients with hypothyroidism had RLS, 5 despite normal thyroid function tests.…”

Neurotransmitters Level in Hypothyroid Male Albino Rats after Isotretinoin Treatment

“…However, Mano et al (1998) reported that there was no difference in body weight between hypothyroid and control rats. Changes in body mass of animals with thyroid dysfunction are probably associated with a longer period of disease occurrence and the induction period has not allowed the observation of such occurrence in Mano et al (1998) study.…”

“…Changes in body mass of animals with thyroid dysfunction are probably associated with a longer period of disease occurrence and the induction period has not allowed the observation of such occurrence in Mano et al (1998) study. As regards the W.P.…”

“…It is widely used also in acne patients suffering from various diseases such as hypothyroidism. The adverse events related to depression suicidal idea and psychosis have been more common with isotretinoin than with other acne treatment such as antibiotics (Mano et al, 1998;Wysowski et al, 2001).…”