Interrelationships of the thyroid and pituitary in embryonic and premetamorphic stages of the frog, Rana pipiens

Kaye, Nancy Weber

doi:10.1016/0016-6480(61)90019-3

Cited by 79 publications

(11 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indirect evidence supporting the presence of negative feedback early in tadpole development dates back to the early 1960s. Studies conducted on both R. pipiens (Kaye 1961) and X. laevis (Dodd & Dodd 1976) showed that treatment with TH suppressed thyroidal activity as measured by a decrease in iodide uptake by the thyroid gland. Similarly, treatment of premetamorphic tadpoles with goitrogens resulted in .…”

Section: Discussionmentioning

confidence: 99%

“…However, they did not directly test whether feedback was in fact absent before climax, and a considerable body of data suggests that negative feedback on pituitary TSH is functional in the premetamorphic tadpole. Kaye (1961) provided evidence that negative feedback can operate from a very early stage of development; i.e. tadpoles of R. pipiens treated with TH at Taylor Kollros stage III exhibited depressed thyroidal 131 I uptake.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Regulation of pituitary thyrotropin gene expression during Xenopus metamorphosis: negative feedback is functional throughout metamorphosis

Manzon¹,

Denver²

2004

Journal of Endocrinology

View full text Add to dashboard Cite

Several hypotheses have been proposed to explain the increase and sustained expression of pituitary thyrotropin (TSH) in the presence of elevated plasma thyroid hormone (TH) concentrations at metamorphic climax in amphibians. It has been proposed that the negative feedback of TH on TSH is inoperative until metamorphic climax, and that it is established at this time by the upregulation of pituitary deiodinase type II (DII); DII converts thyroxine (T 4 ) to 3,5,3 -triiodothyronine (T 3 ). However, earlier investigators, using indirect measures of TSH, reported that TH negative feedback on TSH was functional in premetamorphic tadpoles. In an effort to understand pituitary TSH regulation during amphibian metamorphosis, we analyzed multiple pituitary genes known or hypothesized to be involved in TSH regulation in tadpoles of Xenopus laevis. Tadpole pituitary explant cultures were used to examine direct negative feedback on TSH mRNA expression. Negative feedback is operative in the early prometamorphic tadpole pituitary and both T 3 and T 4 can downregulate TSH mRNA expression throughout metamorphosis. The expression of both DII and TH receptor A mRNAs increased during development and peaked at climax; however, these increases coincided with similar increases in deiodinase type III, which inactivates TH. Moreover, corticotropin-releasing factor (CRF) receptors, CRF binding protein and thyrotropin-releasing hormone receptor type 2 mRNA expression also peaked at climax. Our data suggest that the regulation of TSH is more complex than the timing of DII expression, and likely involves a balance between stimulation of TSH synthesis and secretion by neuropeptides (e.g. CRF) of hypothalamic or pituitary origin, increased pituitary sensitivity to neuropeptides through upregulation of their receptors, and intrapituitary TH levels.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Regulation of pituitary thyrotropin gene expression during Xenopus metamorphosis: negative feedback is functional throughout metamorphosis

Manzon¹,

Denver²

2004

Journal of Endocrinology

View full text Add to dashboard Cite

show abstract

“…On the other hand KAYE (1961) has demonstrated that iodine uptake is 10 times greater during prometamorphosis as compared with that during premetamorphic period. In the prometamorphic period, the follicular cells show well developed rough endoplasmic reticulum and Golgi field.…”

Section: Discussionmentioning

confidence: 98%

“…Using radio-iodine, thyroid activity in relation to metamorphosis has been studied by a number of workers (GORBMAN and EVANS 1941;SAXEN et al, 1957;KAYE, 1961). They have shown that the thyroid activity at this period is very low.…”

Section: Discussionmentioning

confidence: 99%

“…In mammalia it hasbeen demonstrated that TSH injection causes an accelerated uptake and release of iodine and increase in the number of secretory granules containing thyrogrobulin and reabsorbed large colloid droplets that are fused to lysosomes to hydrolyzed the colloid to thyroxine (HERMAN, 1960;WISSIG, 1963;STEIN and GROSS, 1964;WETZEL, et al, 1965;EKHOLM and SMEDS, 1966;HERVEG et al, 1966;SELJELID, 1967a, b, c;FUJITA andSUEMASA 1968, FUJITA, 1969). According to biochemical studies, thyroxine concentration rapidly reaches a peak at stage XX to XXIII (ETKIN, 1964;KAYE, 1961).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Ultrastructural and Cytochemical Studies on the Thyroid Gland of Normal Metamorphosing Frogs (<i>Rana japonica</i> Guenther)

Nanba

1972

Arch. Histol. Jap., Arch. Histol. Jpn

View full text Add to dashboard Cite

Evidence of early pituitary function in the White Leghorn chick

Phillips

1962

Anat. Rec.

View full text Add to dashboard Cite

Interrelationships of the thyroid and pituitary in embryonic and premetamorphic stages of the frog, Rana pipiens

Cited by 79 publications

References 26 publications

Regulation of pituitary thyrotropin gene expression during Xenopus metamorphosis: negative feedback is functional throughout metamorphosis

Regulation of pituitary thyrotropin gene expression during Xenopus metamorphosis: negative feedback is functional throughout metamorphosis

Ultrastructural and Cytochemical Studies on the Thyroid Gland of Normal Metamorphosing Frogs (<i>Rana japonica</i> Guenther)

Evidence of early pituitary function in the White Leghorn chick

Contact Info

Product

Resources

About