Endocrine Abstracts

The hypo and hyperthyroidism alter the synthesis/secretion of pituitary hormones, which in normal conditions present fluctuations in serum concentration during the 24h period. An intrinsic pituitary circadian clock might be related to these oscillations; however, the possible interaction between thyroid hormonal conditions and circadian clock gene expression in anterior pituitary is still unknown. The purpose of this study was to investigate the expression of core circadian cl...

Myocardial gene expression and metabolism fluctuate over the course of the day, in association with changes in energy supply and demand. Recently, time-of-day-dependent oscillations in myocardial processes have been linked to the intrinsic cardiomyocyte circadian clock. Triiodothyronine (T3) is an important modulator of cardiac form and function. The genomic actions of T3 are triggered after its interaction with thyroid hormone nuclear receptors that ofte...

The ingestion of high-fat diet has been considered a crucial factor in the genesis of subclinical systemic inflammation and insulin resistance. The resistance training (RTr) can be an effective tool for the prevention and treatment of immune-metabolic disorders through physiological and morphological adaptations. The purpose of the present study was to analyze the effects of RTr and cessation of training on muscle inflammation and expression of genes related to glucose metabol...

Both metabolism and cardiac function fluctuate over the course of the day according to energy supply and demand. The triiodothyronine (T3) regulates several genes related to metabolism and function in cardiomyocytes. Our previous data have suggested that there is a potential interrelationship between the regulation of cardiac function by T3 and the intrinsic circadian clock in the heart. Considering that: i) the hypothyroidism is associated to a reduction...

The anterior pituitary gland occupies a central position in the hypothalamus–pituitary glands axes and secretes hormones involved in reproduction, growth, and metabolism. The plasma concentrations of pituitary hormones present fluctuations during the 24 h and are markedly altered during the hypothyroidism. The presence of an intra-pituitary circadian oscillator might be related to these oscillations; however, the molecular mechanism and the consequences of the hypothyroid...

TSH is the main regulator of the thyroid hormones (THs) synthesis/secretion, which in turn exert a negative feedback mechanism on the Tshb mRNA expression in the pituitary gland by reducing their transcription rate. Some of triiodothyronine (T3) effects are also shown in short period of time, characterizing the non genomic actions of THs. It has been shown previously that T3 acts on posttranscriptional steps of TSH synthesis and reduces its secre...

Diabetes mellitus (DM) is a disease that results from impairment of insulin synthesis/secretion or signaling. The glycemia of type 1 DM (DM1) patients is controlled by insulin replacement therapy, which chronically results in insulin resistance. We have shown that alloxan-induced diabetic rats present hypothyroidism, and that T3 treatment reduced the inflammatory state and hepatic glucose production and increased insulin sensitivity, improving glycemia control. Considering tha...

Products of carbohydrates, proteins and lipids hydrolysis are absorbed by specific carriers located at the enterocytes apical membrane, but little is known about the mechanisms related to their regulation by own nutrients, especially considering the high consumption of fats. Carbohydrates are transported by SGLT1, GLUT5 and GLUT2 and peptides are transported by PEPT1. Cholesterol is transported by NPC1L1 and long chain fatty acids occur through FAT-CD36 and FATP4. Thyroid horm...

Thyroid hormone plays an important role on carbohydrate and lipid metabolism. In hypothyroidism is observed reduction of glucose transporter-4 expression and insulin sensitivity and in hyperthyroid states the key enzymes of gluconeogenesis and glycogenolysis are induced, and both conditions lead to glucose intolerance. It has been reported an increased prevalence of thyroid dysfunction in obese and diabetic patients. Recently we have demonstrated a hypothyroid state in alloxan...