The acute effects of thyroid hormones on glucocorticoid secretion were studied. Venous blood samples were collected from male rats after they received intravenous 3,5,3'-triiodothyronine (T3) or thyroxine (T4). Zona fasciculata-reticularis (ZFR) cells were treated with adrenocorticotropic hormone (ACTH), T3, T4, ACTH plus T3, or ACTH plus T4 at 37°C for 2 h. Corticosterone concentrations in pla...

Maximum serum thyroxine (T4) and triiodothyronine (T3) levels of healthy calves were seen at 1 day after birth, and thereafter rapidly decreased until 5 days after birth. They stabilized until 2 weeks after birth, then gradually decreased until 4 weeks after birth. Serum T4 levels of calves with endemic goiter tended to be lower than those of healthy ones, but showed similar levels to those of ...

Local 5'-deiodination of serum thyroxine (T4) is the main source of triiodothyronine (T3) for the brain. Since we noted in previous studies that the cerebral cortex of neonatal rats tolerated marked reductions in serum T4 without biochemical hypothyroidism, we examined the in vivo T4 and T3 metabolism in that tissue and in the cerebellum of euthyroid and hypothyroid 2-wk-old rats. We also asses...

To determine the effect of ethanol on peripheral metabolism of T4, deiodinative clearance of T4 and serum concentration of T4, T3 and rT3 were measured in rats isotopically equilibrated with T4. Ethanol 8 g/Kg weight/day was given for 3 days to fasted rats and the results were compared with those normally fed or totally fasted animals. In fasted rats, deiodinative clearance of T4 and serum T4 a...

This work was presented in part at the 53rd Annual Meeting of The American Thyroid Association, Cleveland, Ohio, 7-10 September 1977. Dr. Larsen is an Investigator of the Howard Hughes Medical Institute. Received for publication 29 August 1977 and in revised form 11 January 1978. well with both the change in TSH and the nuclear occupancy, suggesting a linear relationship between the integrated ...

BACKGROUND Recent studies have shown an association between thyroid hormone levels and metabolic syndrome (MetS) among euthyroid individuals; however, there have been some inconsistencies between studies. Here, we evaluated the relationship between thyroid hormone levels and MetS in euthyroid middle-aged subjects in a large cohort. METHODS A retrospective analysis of 13,496 euthyroid middle-a...

introduction: ghrelin, increases food intake, decreases t3 and t4 concentrations and stimulates insulin release, while leptin reduces food intake and suppresses appetite. considering the importance of thyroid hormones, ghrelin and leptin in body metabolism, the purpose of this study was to investigate the effect of interactions between ghrelin and leptin (injected via icv route) and plasma t3 a...

The influence of puberty on sweating patterns of girls exercising in the heat is not known. Nine- to 17-year-old girls, representing 4 stages of breast development: T1 (n = 21); T2 (n = 22); T3 (n = 25); and T4 (n = 22), cycled for 20 min at 60% in 35 °C. The population density of heat activated sweat glands was higher in T1 vs T3 and T4 and in T2 vs T4. Sweat drop area was lower in T1 vs T3 an...