ubiquinone and Thyroid-Diseases

Reactive oxygen species (ROS) have deleterious or beneficial effects; this dual nature of ROS means that ROS act as intracellular signaling molecules and as defense mechanisms against micro-organisms. An overproduction of ROS results in oxidative stress, a deleterious process that damages cell structures, including lipids, proteins, and DNA. Oxidative stress plays a major role in various human disease states, including endocrine dysfunction. As a safeguard against oxidative stress, several endogenous nonenzymatic and enzymatic antioxidant systems exist. Antioxidants can delay or prevent oxidative stress and are widely used in the hope of maintaining health and preventing diseases. Although early studies suggested that antioxidant supplements promoted health, later clinical trials revealed that it may not be true in all cases. In this article, we provide a brief review of the pathophysiologic aspects of oxidative stress in a number of the most commonly human endocrionopathies (diabetes, male and female infertility and thyroid diseases) and review the therapeutic potentials of existing antioxidant strategies. We focus on human clinical trials and discuss the implications of their results. Based on the data reported so far, we conclude that the results reported challenge us to design better antioxidant trials in future, with a particular emphasis on identifying 1) appropriate doses 2) selecting the right populations 3) treating for optimal durations and 4) specific intracellular targeting mechanisms.

Topics: Antioxidants; Ascorbic Acid; Diabetes Mellitus; Female; Humans; Infertility; Male; Oxidative Stress; Reactive Oxygen Species; Thioctic Acid; Thyroid Diseases; Ubiquinone; Vitamin E

Topics: Adolescent; Adult; Coenzymes; Down Syndrome; Female; Humans; Male; Thyroid Diseases; Thyroid Hormones; Thyrotropin; Thyrotropin-Releasing Hormone; Ubiquinone

Serum and tissue CoQ9 levels were determined in hypothyroid, euthyroid and hyperthyroid rats. A significant negative correlation was demonstrated between serum FT4 or T3 and CoQ9 in rats with various states of thyroid functions. Liver CoQ9 was significantly increased in rats rendered mildly hyperthyroid. There was a significant positive correlation between serum FT4 or T3 and liver CoQ9. While liver CoQ9 did not significantly change in severely hyperthyroid animals, liver mitochondrial CoQ9 showed a significant positive correlation with serum T3. Kidney and heart CoQ9 levels did not significantly change in hyperthyroid rats, but those in hypothyroid rats showed a tendency to increase. It was suggested that the synthesis of CoQ9 was increased in the liver in hyperthyroidism.

Topics: Animals; Kidney; Liver; Male; Mitochondria, Liver; Myocardium; Rats; Rats, Inbred Strains; Thyroid Diseases; Thyroxine; Triiodothyronine; Ubiquinone

To investigate the relationship between serum levels of Coenzyme Q10 and cardiac performance in thyroid disorders, we studied the cardiac performance and assessed serum levels of thyroid hormones and Coenzyme Q10 in 20 patients with hyperthyroidism, 5 patients with hypothyroidism and 10 normal subjects. A significant inverse correlation between thyroid hormones and Coenzyme Q10 levels was found by performing partial correlation analysis. Because low serum levels of Coenzyme Q10 were found in thyrotoxic patients and congestive heart failure may occur as a result of severe hyperthyroidism, 120 mg of Coenzyme Q10 was administered daily for one week to 12 hyperthyroid patients and the change in cardiac performance was assessed. Further augmentation of cardiac performance was found in hyperthyroid hearts, which were already augmented, after the administration of Coenzyme Q10. It appears, therefore, that the Coenzyme Q10 dose actually has a therapeutic value for congestive heart failure induced by severe thyrotoxicosis.

Topics: Adolescent; Adult; Aged; Cardiac Output; Coenzymes; Female; Heart; Humans; Hyperthyroidism; Middle Aged; Systole; Thyroid Diseases; Thyroid Hormones; Ubiquinone

The correlation between serum CoQ10 levels and serum thyroid hormones in thyroid disorders was investigated in the present studies. Serum CoQ10 was measured by high speed liquid chromatography utilizing ultraviolet detector. In normal controls, serum CoQ10 level of the male was higher than that of the female. Serum CoQ10 level in hyperthyroidism was significantly lower than that of euthyroid subjects. But in hypothyroidism, serum CoQ10 level did not show any significant difference from that of euthyroid subjects. Significant inverse correlations were demonstrated between log CoQ10 and log T3, log T4, log free T4, or log rT3. These data suggested abnormalities in the mitochondrial electron transport system in thyroid disorders.

Topics: Adolescent; Adult; Aged; Child; Coenzymes; Female; Humans; Hyperthyroidism; Hypothyroidism; Male; Middle Aged; Thyroid Diseases; Thyroid Hormones; Thyroidectomy; Ubiquinone

1. Under conditions of thyrotoxicosis induced by feeding rats with iodinated casein, ubiquinone concentration was found to increase in the liver by increased synthesis and by partly decreased catabolism leading to its accumulation. The increased ubiquinone was found primarily in the mitochondrial and supernatant fractions. 2. Supplementing the diet with thyroxine, at less than toxic doses, also increased the synthesis and the concentration of ubiquinone in the liver. 3. In the condition of hypothyroidism obtained by feeding rats with thiouracil the concentration and the synthesis of ubiquinone in the liver showed a small decrease. 4. Synthesis of ubiquinone in liver slices was partially inhibited by addition of thyroxine in vitro. Therefore the activation effect on ubiquinone synthesis of excess of thyroxine in the intact animals appears to be by an indirect mechanism.

Topics: Animals; Depression, Chemical; Diet; Hyperthyroidism; Hypothyroidism; In Vitro Techniques; Liver; Mitochondria, Liver; Rats; Stimulation, Chemical; Thyroid Diseases; Thyroxine; Ubiquinone