The role of prolactin in blocking thyroxine-induced differentiation of tail tissue in larval and neotenic Ambystoma tigrinum
| Autor: | Marcia A. Christopher, James E. Platt, Constance A. Sullivan |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Gills
Tail medicine.medical_specialty Sodium Period (gene) chemistry.chemical_element Biology Ambystoma Endocrinology Internal medicine medicine Animals Incubation Tiger salamander Larva Body Weight Metamorphosis Biological Cell Differentiation Water-Electrolyte Balance biology.organism_classification In vitro Prolactin Thyroxine chemistry Animal Science and Zoology Antagonism |
| Zdroj: | General and Comparative Endocrinology. 35:402-408 |
| ISSN: | 0016-6480 |
| DOI: | 10.1016/0016-6480(78)90134-x |
| Popis: | Previous work ( J. E. Platt and M. A. Christopher, 1977 , Gen. Comp. Endocrinol. , 31 , 243–248) had shown that a single injection of ovine prolactin (PRL) given to larval or neotenic tiger salamanders retarded tail fin regression induced in these animals with thyroxine (T 4 ). This antagonism of T 4 -induced tail fin regression was correlated with PRL-induced changes in the water and sodium content of tail tissue. The present study presents evidence which demonstrates that the alternation of tail water and sodium levels occurs well within the normal lag period that precedes the morphological manifestations of T 4 -induced tail fin regression. Additional experiments using a simple in vitro incubation system show that larval tail skin pieces maintained in this system increase their water content when incubated for 22 hr with PRL. Incubation of tail skin pieces taken from recently metamorphosed animals under identical conditions does not reveal a response to PRL. Further, untreated larval tail skin maintains a significantly higher water content than untreated tail skin from metamorphosed animals incubated for the same time in vitro . These results are discussed with regard to the mechanism whereby PRL acts to block T 4 -induced tissue differentiation in amphibians. |
| Databáze: | OpenAIRE |
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