Uptake, metabolism and action of triiodothyronine in calf-thyroid slices

Juvenal, Guillermo; Pisarev, Mario A.; Pisarev, Diana L. Kleiman de; Altschuler, N

doi:10.1016/0303-7207(81)90100-3

Cited by 17 publications

(9 citation statements)

References 21 publications

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“…Since an activation of the thyroidal type I 5 -deiodinase by T 3 has been observed (Mori et al 1996), an implication of iodide in the cellular growth response to T 3 should not be discarded. However, most of the T 3 effects on the thyroid tissue do not seem to be due to its deiodination (Pisarev 1985) although slight dehalogenation of T 3 have been reported in calf thyroid slices (Juvenal et al 1981). In agreement, iodide concentrations within the range expected to be generated from total or partial T 3 deiodination did not modify basal thymidine incorporation in our system, supporting the idea that iodide is not involved in the T 3 -induced DNA synthesis.…”

Section: Discussionsupporting

confidence: 85%

“…It has been reported that thyroid tissue takes up and dehalogenates exogenous thyroid hormone (TH) rapidly (Pisarev 1985). Other observations indicate that TH can inhibit thyroid cell function both in vivo and in vitro (Juvenal et al 1981, Akiguchi et al 1992, Spitzweg et al 1999. The presence of nuclear T 3 receptors (T 3 R) in thyroid cells from some species has been well established (Erkenbrack & Rosenberg 1986, Pisarev et al 1986, Nakamura & Imura 1988, Brönnegård et al 1994, raising the possibility that T 3 R could participate in the regulation of gene expression by T 3 in thyroid cells.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tri-iodothyronine induces proliferation in cultured bovine thyroid cells: evidence for the involvement of epidermal growth factor-associated tyrosine kinase activity

Fulvio

Coleoni²,

Pellizas³

et al. 2000

Journal of Endocrinology

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The effects of the tri-iodothyronine (T 3 ) secreted by thyroid cells on the growth of the thyrocyte are poorly known. In this study we analyzed the effects of T 3 on the proliferation of bovine thyroid follicles in primary culture previously depleted of endogenous T 3 . Cellular deoxiribonucleic acid (DNA) synthesis, determined by [ 3 H]thymidine incorporation, was stimulated by T 3 (0·1-5·0 nM) for 24 h in a concentration-dependent fashion with a maximal effect at 1·0 nM T 3 (P<0·01). This T 3 action was time-dependent when assayed from 12 to 72 h. The induction of mitogenic activity was corroborated by the increase in proliferating cell nuclear antigen (PCNA) measured by Western blot analysis. PCNA increased after treatment with T 3 (0·1-5·0 nM) in a concentrationdependent manner. Since T 3 modifies the activity of growth factors whose actions are mainly mediated by tyrosine kinase (TK) activation in diverse cellular types, we assayed the effects of genistein, a general TK inhibitor, and tyrphostin A25, a specific epidermal growth factor (EGF)-receptor (EGFR)-dependent TK activity inhibitor, on the proliferative effects of T 3 . The T 3 -induced [ 3 H]thymidine incorporation was inhibited by both agents in a concentration-dependent manner. A significant increase in the total TK activity measured in cellular protein extracts was induced by 0·5 and 1·0 nM T 3 (P<0·001). Tyrosine phosphorylation of the EGFR was also stimulated by T 3 (P<0·001) with no change in the EGFR expression as determined by Western blot analysis. Both, the T 3 -stimulated [3 H]thymidine incorporation and the TK activity were inhibited by a anti-mouse EGF antibody. These results lead us to propose that T 3 could operate as a proliferative agent in bovine thyroid cells through a mechanism involving an autocrine/paracrine EGF/EGFR-dependent regulation.

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Section: Discussionsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Tri-iodothyronine induces proliferation in cultured bovine thyroid cells: evidence for the involvement of epidermal growth factor-associated tyrosine kinase activity

Fulvio

Coleoni²,

Pellizas³

et al. 2000

Journal of Endocrinology

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“…Both KC104 and ouabain caused some decrease in the T/M ratio, which can partially be explained by a selective impairment in the uptake of the conta¬ minating iodide. The entrance of labelled triiodo¬ thyronine into calf thyroid slices was also unaffec¬ ted by these agents Juvenal et al 1981). A simila¬ rity between the entrance of T4 and T3 was obser¬ ved when the influence of Ca++ was studied.…”

Section: Discussionmentioning

confidence: 99%

Uptake, metabolism and subcellular distribution of [125I]T4 in calf thyroid slices

Chazenbalk

Pisarev

Juvenal

et al. 1984

Acta Endocrinologica

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Previous work from our laboratory has shown that iodothyronines have a direct inhibitory action on the thyroid. In the present studies the uptake, metabolism and subcellular distribution of labelled thyroxine were analyzed. The entry of this hormone reaches a plateau after 15\p=n-\20min incubation and is temperature-dependent. The T/M values for T4 were much lower than those of labelled T3 and the curve was different from that obtained with [125I]. The influence of a series of compounds on the T/M values for thyroxine was studied. KI, T3, IOP PTU and MMI were without effect. Absence of Ca++ in the buffer, or addition of KClO4 or ouabain caused a slight decrease, while TSH produced a stimulation in the T/M ratio. Calf thyroid slices dehalogenated thyroxine, producing both T3 and rT3. TSH increased the generation of these two compounds. Neither PTU nor IOP altered the production of T3 and rT3 significantly. The lack of effect of IOP on T3 and rT3 generation was confirmed in calf thyroid homogenates. However, and in agreement with previous reports, IOP significantly decreased production of both triiodothyronines in rat liver slices and in rat liver homogenates. When the subcellular distribution of labelled thyroxine was examined most of the radioactivity appeared in the soluble fraction and less than 1 % was present in purified nuclei. The addition of unlabelled thyroxine to the slices only caused a significant displacement in the radioactivity of purified nuclei. The presence of labelled thyroxine in the nuclei was confirmed by paper chromatography. lodine has been used for many years in the treat¬ ment of goitre and to relieve symptoms of Graves' disease. Many studies have been performed in order to clarify its mechanism of action (see reviews Wolff 1976; Pisarev & Kleiman de Pisarev 1980).

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“…Different compounds have been proposed to be such mediators, such as an iodoprotein [47] or T 3 [48], but their possible role remains controversial, although it has been postulated that TRβ (one of the receptors for T 3 ) plays a role in thyroid cancer [49]. The biosynthesis of iodolipids has been observed in the thyroid gland from several species and their participation in thyroid auto regulation has been suggested.…”

Section: Mechanisms Of Iodide Actionmentioning

confidence: 98%

Thyroid: Iodine Beyond the Thyronines

Juvenal¹,

Thomasz²,

Oglio³

et al. 2011

curr chem biol

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Although thyroid gland function is mainly under the control of pituitary TSH, other factors may also play a role in this process. Iodine is not used only by the thyroid to synthesize thyroid hormones but also directly influences a number of parameters such as thyroid proliferation and function. Thyroid autoregulation has been related to intraglandular content of an unknown putative iodocompound. The thyroid is capable of producing different iodolipids such as 6-iododeltalactone (ILδ) and 2-iodohexadecanal (2-IHDA). Data from different laboratories have shown that these iodolipids can inhibit several thyroid parameters suggesting that these compounds may be the intermediates in the thyroid autoregulation process.

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Uptake, metabolism and action of triiodothyronine in calf-thyroid slices

Cited by 17 publications

References 21 publications

Tri-iodothyronine induces proliferation in cultured bovine thyroid cells: evidence for the involvement of epidermal growth factor-associated tyrosine kinase activity

Tri-iodothyronine induces proliferation in cultured bovine thyroid cells: evidence for the involvement of epidermal growth factor-associated tyrosine kinase activity

Uptake, metabolism and subcellular distribution of [125I]T4 in calf thyroid slices

Thyroid: Iodine Beyond the Thyronines

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