In our previous study, we observed a tendency towards an age-related increase in the serum thyrotropin (TSH) concentration. Regulatory mechanisms of TSH secretion in elderly subjects were studied. In 43 elderly subjects, serum TSH did not correlate significantly with serum T4, T3 free T4 or rT3. Further, those with increased TSH (greater than 5 mU/l, 9 subjects) did not overlap with those with ...

Thyroid hormone [triiodothyronine (T3)] positively regulates NADPH cytochrome P450 reductase (P450R) mRNA expression in rat liver, with P450R transcription initiation being a key regulated step. T3 is presently shown to have significant post-transcriptional effects on P450R expression. T3 increased the size of cytoplasmic P450R mRNA by approximately 105 nucleotides 12 h after T3 treatment, foll...

In chick embryo hepatocytes (CEH), stimulation of malic enzyme transcription by 3,3',5-tri-iodothyronine (T3) is mediated by a liver-specific and T3-inducible DNase I hypersensitive region (-3910 to -3640 bp) in the malic enzyme gene. Previous studies have shown that this region contains a cluster of five T3 response elements (T3REs), referred to as a T3 response unit (T3RU), plus three accesso...

Normal human PBMC were analyzed for the presence of cells expressing both T3 and NKH1 antigens, using direct two-color immunofluorescence. In six individuals, NKH1+T3+ cells were found to represent 2.5% of PBMC and 24% of the total number of NKH1+ cells. Purified NKH1+T3+ cells were shown to have the typical morphology of large granular lymphocytes (LGL). NKH1+T3+ cells also exhibited spontaneo...

Brown adipose tissue (BAT) thermogenesis increases when uncoupling protein-1 (UCP1) is activated adrenergically and requires T3. In humans, UCP1 activation in BAT seems involved in body weight maintenance. BAT type 2 deiodinase (D2) increases in response to adrenergic agents, producing the T3 required for UCP1 expression. T3 actions are mediated by thyroid hormone nuclear T3 receptors (TR), TRα...

In a previous study, tomato race 3 (T3) strains of Xanthomonas perforans became predominant in fields containing both X. euvesicatoria and X. perforans races T1 and T3, respectively. This apparent ability to take over fields led to the discovery that there are three bacteriocin-like compounds associated with T3 strains. T3 strain 91-118 produces at least three different bacteriocin-like compoun...

It is over 40 years since the original demonstration that thyroxine (T4), the principal secretory product of the thyroid, is deiodinated, to 3,5,3'-tri-iodothyronine (T3) in peripheral mammalian tissues. Subsequently it was shown that the antithyroid drug propylthiouracil (PTU) also blocked the metabolic effects of administered T4 in proportion to its inhibition of T4 to T3 conversion, indicati...

Angiogenesis means the formation of new blood vessels from preexisting vascular, is of fundamental importance in several pathological states such as tumor growth, rheumatoid arthritis, and diabetic retinopathy. Angiogenesis involves a set of steps, including activation and movement of endothelial cells and tube formation. Control of these steps by drugs or dietary food components is a hopeful a...

We have previously demonstrated that 3,5,3'-tri-iodo-L-thyronine (T3) produces a very rapid and transient increase in calcium uptake and cytoplasmic free calcium concentration in the rat thymocyte, and have postulated that Ca2+-ATPase may contribute to the overall effect of T3 on cellular calcium metabolism. In the present study, we show that in the rat thymocyte, T3 increased plasma membrane C...