Interdependence of corticosterone and thyroid hormones in toad larvae (<i>Bufo boreas</i>). II. Regulation of corticosterone and thyroid hormones

Hayes, Tyrone B.; Wu, Tzu Hao

doi:10.1002/jez.1402710205

Cited by 55 publications

(43 citation statements)

References 19 publications

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“…When they were exposed to various concentrations of thyroxine, lower (1-2 μg l −1 ) doses caused tail regeneration, limb development and metamorphosis faster than higher (>3 μg l −1 ) doses. Thyroxine (T4) is known to accelerate amphibian metamorphosis by regulating the gene expression and protein synthesis (Hayes and Wu, 1995;Opitz et al, 2006;Degitz et al, 2005;Oka et al, 2009). The plastic monomer Bisphenol A and related chemicals are known to suppress metamorphosis in Rana rugosa by interfering the binding of hormone to its receptors (Goto et al, 2006).…”

Section: Amputation Of Tail and Treatmentmentioning

confidence: 98%

“…Thyroid hormone is known to promote the amphibian metamorphosis in general (Hayes and Wu 1995;Opitz et al, 2006;Degitz et al, 2005;Oka et al, 2009) while retinoids (vitamin A/retinoic acid/palmitic acid) interfere with limb development and are known to induce homeotic transformation, leading to the appearance of ectopic limbs at the amputated end of the tail (Mahapatra and Mohanty-Hejmadi, 1994;Das and MohantyHejmadi 1998, 1999, 2003Hejmadi and Crawford, 2003). It has been reported that exposure of Xenopus laevis and Bufo bufo larvae to methoprene (an insect growth regulator) and its derivatives results in similar eff ects to those reported for vitamin A when the tail is amputated (Paulov, 1976;Degitz et al, 2003).…”

Section: Introductionmentioning

confidence: 95%

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Developmental disruptions induced by insect growth regulator (Novaluron) in Bufo melanostictus tadpoles

Pancharatna

Ghodageri

Deshpande

et al. 2010

J of Applied Toxicology

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Novaluron is an insect growth regulator (IGR) used against fruit-borers and domestic pests. In this study, effects of different concentrations (0.5, 0.75, 1.0, 1.5 microg l(-1)) of novaluron on the tail regeneration, limb development and metamorphosis were examined in Bufo melanostictus. Thyroxine (1.0, 2.0, 3.5, 5.0 microg l(-1)), which promotes amphibian development/metamorphosis, and vitamin A (5, 20, 40, 60 IU l(-1)), which disrupts development and induce polymelia, were used for comparison. Bufo melanostictus tadpoles were raised in the laboratory from eggs collected around Dharwad in August 2007. The tail of tadpoles was amputated at limb-bud stage under ether anesthesia. Ten tadpoles were exposed to each concentration of chemicals in triplicate for 5 days and then reared in conditioned water. Tadpoles were fed on boiled spinach. In controls (tadpoles exposed to ringer solution), the tail regenerated on the 5th day, hind-limbs and fore-limbs appeared on days 15 and 24, respectively; metamorphosis was complete on the 30th day. In 1 and 2 microg l(-1) thyroxine exposed tadpoles, regeneration of tail, development of limbs and metamorphosis were preponed to the 4th, 7th, 11th and 23rd day respectively. Exposure to vitamin A resulted in the regeneration of laterally drooped tails, delay in limb development and arrest of metamorphosis in all the concentrations used. Novaluron at lower dose (0.5 microg l(-1)) was not effective, but at 0.75 microg and higher concentrations it elicited results comparable to those of vitamin A. The study indicates that novaluron interferes with amphibian development if found as contaminant in the water bodies where amphibians live and reproduce.

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Section: Amputation Of Tail and Treatmentmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 95%

Developmental disruptions induced by insect growth regulator (Novaluron) in Bufo melanostictus tadpoles

Pancharatna

Ghodageri

Deshpande

et al. 2010

J of Applied Toxicology

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“…Thyroid hormones were extracted from whole tadpoles following methods described by Denver (1993Denver ( , 1998a. CORT was extracted from whole tadpoles following the method of Hayes & Wu (1995) with modifications described by Denver (1998a Denver (1998a).…”

Section: Hormone Extraction and Riamentioning

confidence: 99%

Developmental expression and hormonal regulation of glucocorticoid and thyroid hormone receptors during metamorphosis in Xenopus laevis

Krain¹,

Denver²

2004

Journal of Endocrinology

102

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Corticosteroids, the primary circulating vertebrate stress hormones, are known to potentiate the actions of thyroid hormone in amphibian metamorphosis. Environmental modulation of the production of stress hormones may be one way that tadpoles respond to variation in their larval habitat, and thus control the timing of metamorphosis. Thyroid hormone and corticosteroids act through structurally similar nuclear receptors, and interactions at the transcriptional level could lead to regulation of common pathways controlling metamorphosis. To better understand the roles of corticosteroids in amphibian metamorphosis we analyzed the developmental and hormonedependent expression of glucocorticoid receptor (GR) mRNA in the brain (diencephalon), intestine and tail of Xenopus laevis tadpoles. We compared the expression patterns of GR with expression of thyroid hormone receptor beta (TR ). In an effort to determine the relationship between nuclear hormone receptor expression and levels of ligand, we also analyzed changes in wholebody content of 3,5,3 -triiodothyronine (T 3 ), thyroxine, and corticosterone (CORT). GR transcripts of 8, 4 and 2 kb were detected in all tadpole tissues, but only the 4 and 2 kb transcripts could be detected in embryos. The level of GR mRNA was low during premetamorphosis in the brain but increased significantly during prometamorphosis, remained at a constant level throughout metamorphosis, and increased to its highest level in the juvenile frog. GR mRNA level in the intestine remained relatively constant, but increased in the tail throughout metamorphosis, reaching a maximum at metamorphic climax. The level of GR mRNA was increased by treatment with CORT in the intestine but not in the brain or tail. TR mRNA level increased in the brain, intestine and tail during metamorphosis and was induced by treatment with T 3 . Analysis of possible crossregulatory relationships between GRs and TRs showed that GR mRNA was upregulated by exogenous T 3 (50 nM) in the tail but downregulated in the brain of premetamorphic tadpoles. Exogenous CORT (100 nM) upregulated TR mRNA in the intestine. Our findings provide evidence for tissuespecific positive, negative and crossregulation of nuclear hormone receptors during metamorphosis of X. laevis. The synergy of CORT with T 3 on tadpole tail resorption may depend on the accelerated accumulation of GR transcripts in this tissue during metamorphosis, which may be driven by rising plasma thyroid hormone titers.

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“…The roles of Received March 4, 1994;revision accepted September 30, 1994 B, the thyroid hormones, and the interactive effects of B and the thyroid hormones on body growth (length and weight), tail growth and reduction, rear leg growth and development, and FLE were examined. Thiourea (Thio; a goitrogen) and metyrapone (MTP; a n inhibitor of corticoid synthesis) were used in various combinations with B, thyroxine (T4), and triiodothyronine (T3), to determine the mechanism of B's action as well as the role of endogenous B in larval growth and development.…”

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confidence: 99%

Interdependence of corticosterone and thyroid hormones in larval toads (Bufo boreas). I. Thyroid hormone‐dependent and independent effects of corticosterone on growth and development

Hayes

1995

J. Exp. Zool.

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In a previous study (Hayes et al. [1993] J. Exp. Zool., 266:206-215), we demonstrated that exogenous corticosterone (B) inhibited growth, and had varied effects on development and metamorphosis in the toad (Bufo boreas). The current study determined the relation between the actions of B and thyroid hormones on body growth (length and weight), tail growth and reduction (length and height), rear leg growth and differentiation, and foreleg emergence (FLE). Thiourea (Thio; a goitrogen) and metyrapone (MTP; a glucocorticoid synthesis inhibitor) were used to determine the role of endogenous hormones in growth and development. These inhibitors were also used in various combinations with the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), to determine the extent to which B's actions depend on the thyroid hormones. B was ineffective at inducing tail reduction (length and height) in the presence of Thio, but B enhanced the effects of both thyroid hormones, suggesting that the actions of B on the tail were dependent on thyroid hormones. B inhibited body growth even in the presence of Thio, but did not enhance thyroid hormone's inhibition of growth. B alone stimulated foreleg emergence (FLE) and enhanced thyroid hormone's activity on FLE when B and the thyroid hormones were given in combination, but did not induce FLE in the presence of Thio. B stimulated rear leg development, but not in the presence of Thio, suggesting that this effect was due to interactions with thyroid hormones. Furthermore, MTP antagonized the stimulatory effect of T4 on rear leg development, suggesting that endogenous B also interacted with exogenous thyroid hormones.(ABSTRACT TRUNCATED AT 250 WORDS)

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Interdependence of corticosterone and thyroid hormones in toad larvae (Bufo boreas). II. Regulation of corticosterone and thyroid hormones

Cited by 55 publications

References 19 publications

Developmental disruptions induced by insect growth regulator (Novaluron) in Bufo melanostictus tadpoles

Developmental disruptions induced by insect growth regulator (Novaluron) in Bufo melanostictus tadpoles

Developmental expression and hormonal regulation of glucocorticoid and thyroid hormone receptors during metamorphosis in Xenopus laevis

Interdependence of corticosterone and thyroid hormones in larval toads (Bufo boreas). I. Thyroid hormone‐dependent and independent effects of corticosterone on growth and development

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