Effects of streptozocin-induced diabetes and food restriction on quantities and source of T4 and T3 in rat tissues

Elst, J.P. Schröder-van der; Heide, D. van der

doi:10.2337/diabetes.41.2.147

Cited by 13 publications

(14 citation statements)

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“…Several investigators have reported decreased serum TSH as well as T 4 levels 10 to 30 days after DM induction (1)(2)(3)17,18). The decreased TSH has been ascribed to a diminished pituitary sensitivity to TRH (17,19) or to an intrinsic reduction in the constitutive and/or regulated TSH secretion by the diabetic thyrotropes (20).…”

Section: Discussionmentioning

confidence: 99%

“…An impaired function of the hypothalamus-pituitary-thyroid axis, including reduced hypothalamic TRH, decreased serum TRH, TSH, T 4 , and T 3 (1)(2)(3), low thyroid peroxidase activity (4), as well as decreased hepatic and renal T 4 -5'-deiodination have been reported in shortterm streptozotocin-induced diabetes mellitus (3,5,6). The hypofunction of the thyroid gland in diabetic animals has generally been ascribed to decreased serum TSH (1-3), although in some studies serum TSH has been found to be normal (4,5).…”

Section: Introductionmentioning

confidence: 99%

“…The hypofunction of the thyroid gland in diabetic animals has generally been ascribed to decreased serum TSH (1-3), although in some studies serum TSH has been found to be normal (4,5). Pituitary T 4 -5'-deiodinase (DI) activity has also been re-ported to be either normal or reduced in short-term experimental DM (3,6). However, little is known about the thyroid deiodinase activity or about the effects of chronic diabetes mellitus on thyroid function and T 4 -deiodinating activities.…”

Section: Introductionmentioning

confidence: 99%

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Pituitary-thyroid axis in short- and long-term experimental diabetes mellitus

Nascimento-Saba

Breitenbach²,

Rosenthal³

1997

Braz J Med Biol Res

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Short-term experimental diabetes mellitus (DM) produces a significant decrease in serum thyroid hormones, a decreased or normal serum thyroid-stimulating hormone (TSH) and a reduction in hepatic and renal T 4 -5'-deiodination. However, little is known about the effects of chronic diabetes mellitus on the pituitary-thyroid axis function. We evaluated the changes induced by very short-term (6 days), short-term (15 days) and chronic (6 months) streptozotocin-induced diabetes mellitus in 3-month old female Dutch-Miranda rat serum T 4 , serum TSH and T 4 -5'-deiodinase activity in the thyroid and pituitary glands. Serum hormones were determined by specific radioimmunoassays. Iodothyronine-5'-deiodinase activities were assayed in the thyroid and pituitary microsomal fractions using 2 µM T 4 as substrate. Mean serum T 4 was significantly decreased from 3.3 to 2.0 µg/dl 6 days after diabetes mellitus induction, and from 2.2 to 1.5 µg/dl after 15 days of DM, with no significant changes in serum TSH, indicating a decreased pituitary TSH responsiveness to the diminished suppression by T 4 , even though pituitary T 4 -5'-deiodinase activity was unchanged. Thyroid T 4 -5'-deiodinase was unchanged after 6 days of diabetes mellitus, but was significantly increased from 20.6 to 37.0 pmol T 3 /mg protein after 15 days. Six months after diabetes mellitus induction, both serum T 4 and thyroid T 4 -5'-deiodinase returned to normal ranges and serum TSH was unchanged, although pituitary T 4 -5'-deiodinase was now significantly decreased from 2.7 to 1.7 pmol T 3 /mg protein. These findings indicate that some kind of adaptation to chronic insulinopenia may occur at the thyroid level, but this does not seem to be true for the pituitary.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pituitary-thyroid axis in short- and long-term experimental diabetes mellitus

Nascimento-Saba

Breitenbach²,

Rosenthal³

1997

Braz J Med Biol Res

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“…The F-BW ( (5,6,10). At present they are considered as beneficial adaptive responses in situations of limited availability of intracellular energy, when a decrease in T3-dependent catabolic effects is desirable (5)(6)(7)26), although this idea is being reconsidered (26).…”

Section: Introductionmentioning

confidence: 99%

“…Indeed, a return to normal secretion of TSH, accompanied by normalization of the thyroidal release of hormones, is considered as an index that the illness is remitting, or that the metabolic alterations are under control. In the nonpregnant rat with STZ-induced diabetes mellitus these mechanisms are fully operative, and the decreased thyroidal production of the iodothyronines is quantitative very important (10).…”

Section: Introductionmentioning

confidence: 99%

Maternal Diabetes Mellitus, a Rat Model for Nonthyroidal Illness: Correction of Hypothyroxinemia with Thyroxine Treatment Does Not Improve Fetal Thyroid Hormone Status

Calvo¹,

Escobar²,

Rey³

et al. 1997

Thyroid

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Maintenance of normal maternal thyroxinemia prevents severe triiodothyronine (T3) deficiency of the fetus with primary thyroid failure (1). We have studied whether thyroxine (T4) would also protect the fetal brain when maternal hypothyroxinemia is caused by nonthyroidal illnesses. We have used the streptozotocin-induced diabetes mellitus pregnant rat as a model of maternal nonthyroidal illness. We measured the effects of diabetes mellitus, and of correction of the ensuing maternal hypothyroxinemia with T4 as compared to insulin, on maternal body weight, the outcome of pregnancy, glucose, insulin, T4, T3, reverse T3, and thyrotropin levels in the maternal and fetal circulation, as well as T4 and T3 concentrations in tissues, and iodothyronine deiodinases in liver, lung, and brain. The diabetic mothers showed changes in thyroid hormone status typical of nonthyroidal illnesses. Thyroid hormone status of the fetuses was severely affected: the total T4 and T3 pools decreased to one-third of normal values. T4 and T3 concentrations in the fetal brain were lower than normal and the expected increase in 5'-deiodinase activity was not observed. Although insulin treatment avoided or mitigated these changes, the low cerebral T3 did not improve with T4 treatment of the maternal hypothyroxinemia. Several findings indicated that treatment of the severely ill dams with T4 was actually harmful for the outcome of pregnancy. These negative effects were observed without the expected increase in the maternal or fetal T3 pools.

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Neural and Hormonal Responses to Prolonged Cold Exposure

Himms‐Hagen

1996

Comprehensive Physiology

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Effects of streptozocin-induced diabetes and food restriction on quantities and source of T4 and T3 in rat tissues

Cited by 13 publications

References 0 publications

Pituitary-thyroid axis in short- and long-term experimental diabetes mellitus

Pituitary-thyroid axis in short- and long-term experimental diabetes mellitus

Maternal Diabetes Mellitus, a Rat Model for Nonthyroidal Illness: Correction of Hypothyroxinemia with Thyroxine Treatment Does Not Improve Fetal Thyroid Hormone Status

Neural and Hormonal Responses to Prolonged Cold Exposure

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