Stimulation of Alpha Aminoisobutyric Acid-C<sup>14</sup>by Thyrotropin Uptake in Thyroid Slices

Debons, AF; PlTTMAN, J. A.

doi:10.1210/endo-70-6-937

Cited by 25 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, the present report shows that insulin and IGF-I can independently increase amino acid transport in WRT cells and that their effects are additive. The ability of TSH to increase amino acid transport in thyroid slices and in primary cultures of thyroid cells has already been reported (44)(45)(46)(47)(48), as it has the ability of insulin and IGF-I to increase amino acid transport in target cells for these hor¬ mones (32,40,49,50). The data also show that in¬ sulin and TSH have additive effects on amino acid transport, whereas the combination of IGF-I and TSH has a potentiating effect.…”

Section: Discussionmentioning

confidence: 57%

Regulation of amino acid transport in rat and human thyroid cells

Rotella

Piani²,

Frediani³

et al. 1989

Acta Endocrinologica

View full text Add to dashboard Cite

To clarify the role of insulin, IGF-I and TSH in thyroid cell regulation, their effects on amino acid transport were studied separately. These effects were noted and compared using both the Wistar rat thyroid cell line and human thyroid cell cultures. Insulin, IGF-I and TSH were able independently to induce the radiolabelled \ g=a\ \ x=r eq-\ aminoisobutyric acid transport within the rat thyroid cells: TSH stimulated the amino acid transport in rat thyroid cells in a dose-dependent way from 1 pmol/l to 10 nmol/l. Similarly, insulin increased amino acid transport significantly from 0.17 nmol/1 up to 0.17 \g=m\mol/land IGF-I from 0.13 pmol/l up to 0.13 \g=m\mol/l.The combined effects of insulin and TSH on amino acid transport were equal to the theoretical sum of the activities, whereas those of IGF-I and TSH were greater than the theoretical one.When human thyroid cell cultures were used, a significant increase of labelled amino acid transport was induced by TSH, i.e. from 0.1 pmol/l to 10 pmol/l; IGF-I stimulated amino acid transport in a range from 0.13 pmol/l to 13 pmol/l, under the same conditions. Conversely, only large doses of insulin, i.e. 1.7 nmol/l, were able weakly to stimulate amino acid transport. When submaximal TSH and IGF-I doses were co-incubated in human thyroid cells, an additive effect on amino acid transport was observed.Insulin and insulin-like growth factor I are two re¬ lated peptides which play an important role in the growth and differentiation of several organs (1-8) including the thyroid gland (9-16). The existence of IGF-I receptors on thyroid cells in different species has recently been demonstrated ( 17-20). It has been postulated that IGF-I is involved in a paracrine mechanism oí action at the thyroid level (21). Strong evidence suggests that there is an autocrine secretion of IGF-I by ovine and human thyroid cells (17-19, 22,23).IGF-I and insulin potentiate the mitogenic ef¬ fects of TSH on FRTL-5 cells (9, 10), on Wistar rat thyroid cells (WRT cells, 24) and on human thyroid follicles in suspension culture (25). However, while insulin exerts the same effects on differentiated normal human thyroid cells (26), conflicting re¬ sults have been found as to the IGF-I mitogenic ef¬ fect in human thyroid cell monolayers (23,25). Since insulin is a mitogen which acts on the WRT cell line alone (24), the biological action of the pep¬ tides may vary according to species and ex¬ perimental models. The aim of this study was to examine further the role of insulin and IGF-I in regulating thyroid cell function under different conditions, on the as¬ sumption that the biological action of the peptides is not limited to the stimulation of cell prolifera¬ tion (3,8,(27)(28)(29)(30)(31)(32)(33). With this purpose, the single and combined effects of insulin, IGF-I, and TSH on a sodium-dependent, cyclohexamide-sensitive transport of radiolabelled a-aminoisobutyric acid were studied in WRT clonal cells and human thy¬ roid cells in primary culture.

show abstract

Section: Discussionmentioning

confidence: 57%

Regulation of amino acid transport in rat and human thyroid cells

Rotella

Piani²,

Frediani³

et al. 1989

Acta Endocrinologica

View full text Add to dashboard Cite

show abstract

“…This can be attributed to several factors: modified permeability of epithelial cell membranes, different rates of blood flows and/or changed capacity of the cells to synthesize proteins. lt has been reported that the first two processes are modified in the glands of hypo-and hyperstimulated animals (Debons and Pittman 1962, Tong 1964, Segal, Roth, Blair and Bertoli 1966, Clayton and Szego, 1967, Kapitola, Schüllerova and Schreiberova 1971.…”

Section: Discussionmentioning

confidence: 97%

Protein Metabolism in Hypo- and Hyperstimulated Rat Thyroid Glands. - I. Protein Synthesis of Different Thyroidal Proteins

Pavlović-Hournac¹,

Delbauffe²

1975

Horm Metab Res

View full text Add to dashboard Cite

show abstract

“…The endoplasmic reticulum, and thereby probably MV, is known to play a central role in the formation of protein in the follicular epithelium (Nadler et al 1964, Ekholm et al 1966. It is therefore reasonable to assume that MV are connected with the increased rate of protein synthesis probably occurring in toxic glands analogous to the findings in stimulated rat thyroids (Debons et al 1962, Raghupathy et al 1963, Tong 1964.…”

Section: "mentioning

confidence: 94%

Marginal Vacuoles in Fine Needle Aspiration Biopsy Smears of Toxic Goiters

Nilsson

1972

Acta Pathologica Microbiologica Scandinavica Section A Patholog

View full text Add to dashboard Cite

A special type of vacuoles, called marginal vacuoles, and occurring in the cytoplasm of the follicular epithelium cells in smears from fine needle aspiration biopsy specimens is described. Marginal vacuoles were found to be much more frequent in toxic than in atoxic goiters. The difference was so clear that it was considered to be of some value in the examination of biopsy smears from the thyroid. I t is suggested that markedly dilated cisterns of the endoplasmatic reticulum are the most likely ultrastructural counterparts of the vacuoles.

show abstract

Stimulation of Alpha Aminoisobutyric Acid-C¹⁴by Thyrotropin Uptake in Thyroid Slices

Cited by 25 publications

References 0 publications

Regulation of amino acid transport in rat and human thyroid cells

Regulation of amino acid transport in rat and human thyroid cells

Protein Metabolism in Hypo- and Hyperstimulated Rat Thyroid Glands. - I. Protein Synthesis of Different Thyroidal Proteins

Marginal Vacuoles in Fine Needle Aspiration Biopsy Smears of Toxic Goiters

Contact Info

Product

Resources

About

Stimulation of Alpha Aminoisobutyric Acid-C14by Thyrotropin Uptake in Thyroid Slices

Cited by 25 publications

References 0 publications

Regulation of amino acid transport in rat and human thyroid cells

Regulation of amino acid transport in rat and human thyroid cells

Protein Metabolism in Hypo- and Hyperstimulated Rat Thyroid Glands. - I. Protein Synthesis of Different Thyroidal Proteins

Marginal Vacuoles in Fine Needle Aspiration Biopsy Smears of Toxic Goiters

Contact Info

Product

Resources

About

Stimulation of Alpha Aminoisobutyric Acid-C¹⁴by Thyrotropin Uptake in Thyroid Slices