Development of the Hypothalamic-Pituitary-Thyroid Axis in the Neonatal Rat

Dussault, Jean H.; Labrie, Fernand

doi:10.1210/endo-97-5-1321

Cited by 234 publications

(124 citation statements)

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“…4), describing the developmental profile of serum T4 and T3 in the mouse, are the only available ontogenetic data for thyroid hormones in this species. The data for mouse correspond in general to data described for rat (15,36) where serum total and free T4 and T3 concentrations are low at birth and increase progressively during the first 3-4 wk of postnatal life (15,36). In the mouse, (Fig.…”

Section: Discussionsupporting

confidence: 82%

Ontogenesis of Nerve Growth Factor and Epidermal Growth Factor in Submaxillary Glands and Nerve Growth Factor in Brains of Immature Male Mice: Correlation with Ontogenesis of Serum Levels of Thyroid Hormones

et al. 1982

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Summarybetween 11 and 32 days of age. The known increase in mouse serum testosterone to adult male levels between 4-12 wk of age Using specific and sensitive radioimmunoassa~s for may be a factor in the late increase in NGF and EGF elevations growth factor (NGF) and epidermal growth factor (EGF), we after 32 days of age. studied the developmental profde of NGF and EGF concentrations in male mouse submaxillary gland (SMG) from 2-60 days of age. We measured NGF concentrations in mouse cerebellum, cerebral Nerve growth factor (NGF) and epidermal growth factor (EGF) cortex, and brain stem from ages 2-32 days. In addition, we are found in highest concentrations in the submaxillary gland assessed mouse serum thyroxine (T4) and triiodothyronine (T3) (SMG) of the adult male mouse (13,22). Both proteins are found levels in SePerate groups of animals ranging from 5-50 days of in peritubular cells (32,35) and are released concomitantly into age. Mean SMG EGF content and concentration exceeded that saliva (16,27). ~0 t h have C-terminus arginine residues (2, 13) and of NGF between 2 and 18 days of age. At all subsequent ages, exist in SMG as high molecular weight complexes with specific however, mean NGF and EGF content and concentration were arginine esteropeptidase subunits (34). In addition, both NGF, similar. SMG NGF and EGF content were low at 2 days of age, and EGF are found in higher concentrations in male than in decreased slightly through 8 days of age, and increased exponen-female glands. The concentration of both peptides in SMG is tially after 11 days of age with three phases of increase being increased by androgens (10, 17). Bynny et al. (9) described the apparent for both proteins. In the first phase, mean SMG NGF ontogenetic profile of radioimmunoassayable SMG EGF content and EGF contents increased 2.4 and 2.3-fold respectively between from 15 days ofage through adulthood. ~l~~ and ~~~i -~~~ 11 and 18 days of age. A second phase of increase was noted (3) have traced the developmental pattern of SMG NGF concenbetween 18 and 32 days when NGF and EGF increased 9g45-and trations after 20 days using an in vitro bioassay. Murphy et al. (26) 7805-fold respectively. In phase three (32-60 days of age) more have suggested that NGF and EGF are present in equal concenmodest increases of 6.5-fold in mean NGF and EGF content were trations in mature male mouse SMG; however, simultaneous noted.measurements of SMG NGF and EGF concentrations during Cerebellar NGF on cent rations hcreased from 681 to 2241 p d postnatal development in the mouse have not been conducted. mg protein between ages 2 and 15 days and subsequently feu aIn earlier reports we have described significant concentrations plateau level of 1304 pg/mg protein by age 18 days. Cerebral of radioimmunoassayble NGF in brain tissue of adult and develcortical NGF concentrations increased steadily from 251 to 1383 oping mice (37,40) but have not developed a complete ontogenetic p d m g protein between ages 2 and 32 days, w l~r e a s brain stem profile; moreover, we have...

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Section: Discussionsupporting

confidence: 82%

Ontogenesis of Nerve Growth Factor and Epidermal Growth Factor in Submaxillary Glands and Nerve Growth Factor in Brains of Immature Male Mice: Correlation with Ontogenesis of Serum Levels of Thyroid Hormones

et al. 1982

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“…The plasma concentration of TSH is high neonatally (14) and since the hypothalamo -pituitary-thyroid axis changes dramatically in the neonatal period (15) TSH was administrated periodically for a longer period. TSH (T-3538, Sigma Chemical Co., St Louis, MO, USA) was dissolved in PBS and administered i.p.…”

Section: Neonatal Stimulation By Nai and Tshmentioning

confidence: 99%

Neonatal stimulation of the thyroid gland with iodine or suppression during adolescence with triiodothyronine changes the prevalence of autoimmune thyroiditis in BB rats

#M-L|#Hartoft-Nielsen|#

Kaas

et al. 2004

European Journal of Endocrinology

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Objective: Changes in the functional state of beta cells by neonatal stimulation or adolescent suppression have reduced the incidence of type 1 diabetes mellitus in animal models. The aim of this study was to evaluate the effect of manipulation of the activity of the thyroid gland by neonatal stimulation or by adolescent suppression on the prevalence of spontaneous autoimmune thyroiditis (AIT) in rats. Methods: Bio-Breeding/Worcester (BB) rats were treated neonatally with sodium iodine (NaI) or thyroid stimulating hormone (TSH), or during adolescence by triiodothyronine (T 3 ), and the lymphocytic infiltration in the thyroid gland was evaluated. Results: Neonatal treatment with NaI decreased the prevalence of AIT to 32^9% compared with 66^5% in the controls (P , 0.002), mainly caused by a reduction among the female rats (13^9% vs 52^8%, P , 0.006). TSH had no effect. Post neonatal suppression of the thyroid gland by T 3 had a biphasic response. Early in adolescence the overall prevalence was 14^7% compared with 66^5% in the controls (P , 10 25 ); for female rats AIT was prevented (0^0%) compared with 52^8% in the controls (P , 0.0003) and in male rats the values were 29^13% compared with 80^6% in the controls (P , 0.001). Treatment with T 3 later in adolescence increased the overall prevalence to 81^7% compared with 66^5% in the controls (not significant). For female rats the prevalence increased to 78^9% compared with 52^8% in the controls (P ¼ 0.04). The degree of thyroiditis among the affected animals was similar in all groups. Conclusion: Neonatal stimulation of the thyroid gland by iodine or early adolescent suppression by T 3 reduced the prevalence of AIT whereas T 3 given later increased the prevalence of thyroiditis in rats.

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“…In order to demonstrate whether thyroid hormone is involved in the regulation of COX isoforms in the rat heart, we used a hypothyroid rat model. It has been determined in the rat that circulating thyroid hormone levels begin to rise at birth, surge 4 days after birth, and reach mature levels by 16 days postnatally [37]. If thyroid hormone does indeed regulate the developmental transition of the VIa and VIII isoforms, then the hearts from hypothyroid neonates should express the liver form predominantly, as in the 18-day fetal hearts.…”

Section: Figure 1 Developmental Time Course Of Cox Isoform Expressionmentioning

confidence: 99%

“…Furthermore thyroid hormone has previously been shown to regulate the expression of contractile proteins in muscle, causing a developmental switch of myosin heavy chain (MHC) isoforms in cardiac and skeletal muscle [35,36]. The switch of isoforms in rats is associated with the accumulation of serum thyroxine levels, starting at 2 days after birth [37] and reaching maximal levels by day 16. By 28 days after birth, the tri-iodothyronine form of thyroid hormone and the adult form of the heavy chain, α-MHC, reach mature levels in the rat [36,37].…”

Section: Introductionmentioning

confidence: 99%

“…The switch of isoforms in rats is associated with the accumulation of serum thyroxine levels, starting at 2 days after birth [37] and reaching maximal levels by day 16. By 28 days after birth, the tri-iodothyronine form of thyroid hormone and the adult form of the heavy chain, α-MHC, reach mature levels in the rat [36,37]. It is not known whether thyroid hormone regulates or influences the transition of COX isoforms during development.…”

Section: Introductionmentioning

confidence: 99%

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Influence of thyroid hormone on the tissue-specific expression of cytochrome c oxidase isoforms during cardiac development

Meehan

Kennedy

1997

Biochemical Journal

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In mammals, cytochrome coxidase (COX) is composed of 13 different protein subunits. In the rat, two nuclear-encoded subunits, COX VIa and VIII, exist as tissue-specific isoforms: heart and liver. Using Northern-blot analysis, the levels of transcripts for the heart and liver isoforms of VIa and VIII were examined in developing rat hearts. The liver isoform was found to be the predominant form of subunit VIa and the exclusive form of VIII in the 18-day fetal hearts. The mRNA levels of the heart isoform of both subunits increased dramatically to reach adult levels by 14 days. Although the levels of the VIa- and VIII-liver isoform mRNAs remained stable throughout early development, their levels decreased by 40 and 36% respectively between the 18-day fetal stage and 18-day neonatal stage. Therefore the up-regulation of the heart isoforms and down-regulation of the liver isoforms appear to be regulated in a co-ordinated manner during development. To determine if thyroid hormone influences the expression of these developmentally regulated isoforms, the RNA was also extracted from the hearts of 2-week-old hypothyroid rats. The results showed that the levels of VIII-heart and VIa-liver COX mRNAs were approx. 40% lower in the hypothyroid hearts, while VIII-liver and VIa-heart COX isoform expression remained unchanged. These data demonstrate that the isoforms of COX subunits VIa and VIII are not co-ordinately regulated by changes in thyroid hormone levels. Therefore we conclude that, although thyroid hormone influences the expression of isoforms, it appears to do so via a different mechanism from that which regulates the developmental transition.

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Development of the Hypothalamic-Pituitary-Thyroid Axis in the Neonatal Rat

Cited by 234 publications

References 9 publications

Ontogenesis of Nerve Growth Factor and Epidermal Growth Factor in Submaxillary Glands and Nerve Growth Factor in Brains of Immature Male Mice: Correlation with Ontogenesis of Serum Levels of Thyroid Hormones

Ontogenesis of Nerve Growth Factor and Epidermal Growth Factor in Submaxillary Glands and Nerve Growth Factor in Brains of Immature Male Mice: Correlation with Ontogenesis of Serum Levels of Thyroid Hormones

Neonatal stimulation of the thyroid gland with iodine or suppression during adolescence with triiodothyronine changes the prevalence of autoimmune thyroiditis in BB rats

Influence of thyroid hormone on the tissue-specific expression of cytochrome c oxidase isoforms during cardiac development

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