Effects of ions on TSH stimulation of P-32 incorporation into thyroid slice phospholipid

Oka, Hiroyuki; Jb, Field

doi:10.1152/ajplegacy.1966.211.6.1357

Cited by 24 publications

(4 citation statements)

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“…However, the effect of TSH was significantly diminished when it was added to slices exposed to the hormone during the first incubation. In contrast to the results obtained when glucose oxidation was measured, the stimulatory effect of acetylcholine on 32p; incorporation into phospholipids (9) was decreased in thyroid slices exposed to TSH during the first incubation.…”

Section: Resultscontrasting

confidence: 98%

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Inhibition of thyroid-stimulating hormone stimulation of protein kinase, glucose oxidation, and phospholipid synthesis in thyroid slices previously exposed to the hormone.

Field¹,

Bloom²,

C³

et al. 1977

J. Clin. Invest.

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A B S T R A C T Prior exposure ofthyroid slices to thyrotropin (TSH) induced refractoriness to subsequent stimulation of the cyclic AMP system by the hormone. Although the inhibition is incomplete, we examined whether the reduction in cyclic AMP was sufficient to alter other metabolic effects of TSH. Bovine or dog thyroid slices were incubated with or without 5-100 mU/ml TSH for 1-2h, washed, and then incubated without hormone for 1-2 h. Half of the slices not exposed to TSH initially were then incubated with buffer and half were exposed to 5-100 mU/ml TSH. Slices initially incubated with TSH were also incubated with or without TSH in the third incubation. During the refractory period, TSH activation of protein kinase was inhibited even though the hormone still caused some increase in cyclic AMP concentrations. However, protein kinase activity was fully responsive to dibutyryl cyclic AMP when slices were incubated with it during the third incubation. Stimulation of glucose oxidation by TSH was significantly decreased in thyroid slices previously incubated with the hormone. During refractoriness, stimulation of glucose oxidation caused by prostaglandin E1 and dibutyryl cyclic AMP was also significantly diminished but that due to acetylcholine was not. Thus even though dibutyryl cyclic AMP could fully activate protein kinase activity during refractoriness, its effect on glucose oxidation was still inhibited, suggesting that the metabolic block responsible for this refractoriness was distal to activation of protein kinase. Stimulation of 32P, incorporation into phospholipid by TSH and acetylcholine was Received for publication 23 August 1976 and in revised form 29 November 1976. also inhibited during refractoriness. Despite reduction of the stimulatory effect of TSH, binding of 125I1 TSH was not modified by prior incubation of thyroid slices with TSH. These results indicate that changes in the TSH receptor are not responsible for the development of refractoriness and other metabolic sites besides activation of adenylate cyclase appear to be involved.

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Section: Resultscontrasting

confidence: 98%

“…Incorporation of 32P, into phospholipids was determined as previously described (9). Acetylcholine was added during the third incubation to some slices which had been incubated with and without TSH during the initial incubation.…”

Section: Introductionmentioning

confidence: 99%

Inhibition of thyroid-stimulating hormone stimulation of protein kinase, glucose oxidation, and phospholipid synthesis in thyroid slices previously exposed to the hormone.

Field¹,

Bloom²,

C³

et al. 1977

J. Clin. Invest.

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“…A similar conclusion concerning these two effects of TSH has also been presented (14). The interpretation of these in vitro effects of LATS on glucose oxidation and phospholipid synthesis in relation to a possible etiologic significance in thyrotoxicosis must remain speculative.…”

Section: Resultssupporting

confidence: 65%

“…For longer incubations, asp was added to the flasks 2 hr before the termination of the experiment. 3'P incorporation into phospholipids was measured as previously reported (14). In the experiments in which the effects of TSH and LATS on glucose oxidation by liver, kidney, spleen, and testes slices were studied, these tissues were obtained from the same dog whose thyroid gland was used.…”

Section: Methodsmentioning

confidence: 99%

In vitro stimulation by long-acting thyroid stimulator of thyroid glucose oxidation and 32P incorporation into phospholipids

Field¹,

Remer²,

Bloom³

et al. 1968

J. Clin. Invest.

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AB s T R A C T Long-acting thyroid stimulator (LATS) increased glucose oxidation and 32P incorporation into phospholipids in in vitro experiments with dog thyroid slices. The time course of the response was different from that obtained with thyroid-stimulating hormone (TSH), but was very similar to the delayed effect observed in vivo. During a 45 min incubation, TSH, but not LATS increased glucose oxidation, whereas in longer experiments up to 6 hr, both substances augmented 14CO2 production. Amounts of pooled human gamma globulin equivalent to LATS were inactive. Although TSH stimulated 32P incorporation into phospholipids during a 2 hr incubation, LATS was ineffective. In longer incubations, from 41 to 8 hr. LATS did increase 32P incorporation.The stimulatory effect of LATS was not abolished by anti-TSH antibody capable of neutralizing human TSH. Effects of LATS were also obtained with beef and pig thyroid slices. In addition to stimulation of glucose oxidation in dog thyroid slices, LATS occasionally also stimulated glucose oxidation in dog spleen and liver slices. Despite a 54-fold increase in LATS concentration, a satisfactory dose-response curve could not be demonstrated when 14C02 production was measured.

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Thyroid hormone inhibition of intermediary metabolism in dog thyroid slices stimulated by different agonists

Pasquali

Bellastella

Field

1991

J Endocrinol Invest

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The role of thyroid hormones in a short loop feedback in the thyroid is controversial. This process was studied in dog thyroid slices stimulated by TSH, carbachol and phorbol esters. Incubation of thyroid slices with T3 and T4 for 1 hour inhibited the subsequent stimulation of glucose oxidation induced by carbachol and phorbol esters but not by TSH. T3 also inhibited the stimulation of 32P incorporation into phospholipids stimulated by these two agonists. Glucose oxidation stimulated by TSH, carbachol and 12-0-tetradecanoyl-phorbol-13-acetate (TPA) was inhibited by rT3 and the inhibition was not reversed by methimazole, which did abolish the inhibition induced by iodide, MIT and DIT. TSH stimulation of cAMP was not blocked by T3 or T4 but was by rT3 and MIT- and DIT. The mechanism of such inhibition appears to be complex, possibly involving formation of iodide from rT3, MIT and DIT but also dependent on the intact iodothyronine. Moreover, our data suggest that T3 and T4 exert their inhibition on the thyroid through the phospholipids cascade and this mechanism is probably independent on the release of iodide from these iodocompounds.

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Effects of ions on TSH stimulation of P-32 incorporation into thyroid slice phospholipid

Cited by 24 publications

References 0 publications

Inhibition of thyroid-stimulating hormone stimulation of protein kinase, glucose oxidation, and phospholipid synthesis in thyroid slices previously exposed to the hormone.

Inhibition of thyroid-stimulating hormone stimulation of protein kinase, glucose oxidation, and phospholipid synthesis in thyroid slices previously exposed to the hormone.

In vitro stimulation by long-acting thyroid stimulator of thyroid glucose oxidation and 32P incorporation into phospholipids

Thyroid hormone inhibition of intermediary metabolism in dog thyroid slices stimulated by different agonists

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