Search results for "Thyroid hormones"

Thyroid hormone controls carnitine status through modifications of gamma-butyrobetaine hydroxylase activity and gene expression.

2002

The carnitine system plays a key role in beta-oxidation of long-chain fatty acids by permitting their transport into the mitochondrial matrix. The effects of hypothyroidism and hyperthyroidism were studied on gamma-butyrobetaine hydroxylase (BBH), the enzyme responsible for carnitine biosynthesis in the rat. In rat liver, BBH activity was decreased in the hypothyroid state and increased in hyperthyroid animals. The modifications in BBH activity correlated with changes in the enzyme Vmax values. These changes were shown to be related to hepatic BBH mRNA abundance. Thyroid hormones are known to interact with lipid metabolism, in particular by increasing long-chain fatty acid oxidation through…

Characterization of thyroid hormone sulfotransferases

1998

Sulfation is an intriguing pathway of thyroid hormone metabolism since it facilitates the degradation of the hormone by the type I deiodinase (D1). This study reports the preliminary characterization of iodothyronine sulfotransferase activities of rat and human liver cytosol and recombinant rSULT1C1 and hSULT1A1 isoenzymes. All these enzyme preparations catalyzed the sulfation of--in decreasing order of efficiency--3,3'-diiodothyronine (3,3'-T2)3,3',5-triiodothyronine (T3) approximately 3,3',5'-triiodothyronine (rT3)thyroxine (T4). 3,3'-T2 sulfotransferase activity was found to be higher in male than in female rat liver, which has also been shown by others for the expression of rSULT1A1 and…

Favorable clinical heart and bone effects of anti-thyroid drug therapy in endogenous subclinical hyperthyroidism

2007

Although subclinical hyperthyroidism (SCH) has been associated with increased risk of osteoporosis and cardiac arrhythmias, its treatment is still controversial. This study was designed as a prospective, randomized, intervention, control-study with a 1-year follow-up in order to investigate whether normalization of serum TSH in SCH using methimazole has favorable bone and heart clinical effects. Fourteen patients with endogenous SCH (not Graves' disease) were enrolled, 7 (5 women/2 men; group T) were treated with methimazole (2.5-7.5 mg/day), and 7 (5 women/2 men; group C) were followed without treatment; 10 healthy subjects were also included in the study as controls. Serum free-T3 (FT3), …

Terminal or truncal ligation of the inferior thyroid artery during thyroidectomy? A prospective randomized trial.

2016

Abstract Introduction Thyroidectomy is a common procedure in general and endocrine surgery. The technique of ligation of inferior thyroid artery (ITA) has been invoked as a possible cause of appearance of postoperative hypocalcemia. Methods We performed a prospective randomized study involving 184 patients undergoing total thyroidectomy to evaluate the differences of truncal ligation versus distal ligation of ITA in terms of postoperative hypocalcemia, vocal fold palsy, voice and swallowing impairment. The patients were divided into group A (trunk ligation of ITA) and group B (terminal branches ligation of ITA). Results We evaluated postoperative PTH and calcemia (immediate, 6 and 12 months…

Role of thyroid state on induction by ciprofibrate of laurate hydroxylase and peroxisomal enzymes in rat liver microsomes.

1993

The effects of hypothyroidism and hyperthyroidism upon liver microsomal omega-laurate hydroxylase activity (cytochrome P450 IV A1-dependent), peroxisome proliferation marker enzyme activities and acyl CoA oxidase (AOX) expression induced by ciprofibrate (2 mg/kg/day during 8 days) were studied in the male Wistar rat so as to clarify firstly the possible involvement of thyroid hormones in the modification of peroxisomal ciprofibrate-induced enzyme activities in relation to hepatic microsomal cytochrome P450 IV A1 induction, and secondly the possible direct effect of thyroid hormones on the gene expression of specific peroxisomal enzymes. No significant change was found in the ciprofibrate-in…

PIPPIN SUMOYLATION IS CONTROLLED BY THYROID HORMONES

2006

REGULATION OF THE EXPRESSION OF RNA-BINDING PROTEINS IN DEVELOPING AND ADULT RAT BRAINS: ROLE OF THYROID HORMONES

2005

EFFECTS OF THYROID HORMONES ON RNA-BINDING PROTEINS EXPRESSED IN DEVELOPING RAT BRAIN

2005

Hypothyreose, Hyperthyreose und Therapie mit Schilddrüsenhormonen: Einflüsse auf das Skelettsystem

2008

Molecular orbital studies on brominated diphenyl ethers. Part II—reactivity and quantitative structure–activity (property) relationships

2005

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants and are increasingly turning up in the environment. Their structural similarities to polychlorinated biphenyls and thyroid hormones suggest they may be a risk to human health. The present study examines the reactivity of brominated diphenyl ethers (BDEs) on the basis of the electronic structures as calculated by semiempirical AM1 self-consistent field molecular orbital (SCF-MO) method. Frontier orbital energies were used to elucidate the reactivity of BDEs in electrophilic, nucleophilic and photolytic reactions. From an examination of the frontier electron densities, the regioselectivity, or orientation, of metabolic…