Antihistamines and Thyroxine Metamorphosis in Tadpoles
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چکیده
منابع مشابه
Uracil Metabolism in Tadpoles during Thyroxine-induced Metamorphosis.
Previous work in this laboratory (1) has shown that an increase in carbamyl phosphate synthetase activity in the livers of thyroxine-treated tadpoles is the result of protein synthesis de 1u)vo. This induction of the synthesis of a specific enzyme protein by thyroxine was found to be inhibited by chloramphenicol and thiouracil (2). A subsequent survey (3) of several purine and pyrimidine deriva...
متن کاملInhibition of thyroxine-induced metamorphosis by prolactin in tadpoles, Rana catesbeiana.
Thyroxine (T4)-prolactin interactions on hepatic arginase and ornithine transcarbamylase (OTC) as well as hind legs, tail, digestive tract and median eminence were investigated in tadpoles, Rana catesbeiana. Prolactin completely blocked T4-induced tail resorption, but failed to suppress hind-leg growth, shortening of digestive tract and promotion by T4 of the median eminence development. Prolac...
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Xenopus laevis tadpoles that arrest development and remain as larvae for several years sometimes occur spontaneously in laboratory populations. These tadpoles cease development at an early hindlimb stage, but continue to grow and develop into grossly deformed giants. Giant tadpoles lack thyroid glands, and differ in morphology and behaviour from normal larvae. They are negatively buoyant, typic...
متن کاملAge factor in the induced metamorphosis of thyroidectomized tadpoles.
Three age-groups of thyroidectomized tadpoles of Rana catesbeiana were treated with a series of the same graded increasing concentrations of thyroxin. Normal froglets were formed from the three groups at the end of the induced metamorphosis. Growth and metamorphosis were compared. It was found that while the growth rate was a function of ageing, the pattern and rate of metamorphosis were not af...
متن کاملEffects of developmental and growth history on metamorphosis in the gray treefrog, Hyla versicolor (Amphibia, Anura).
In ecological models, the timing of amphibian metamorphosis is dependent upon rate of larval growth, e.g., tadpoles that experience a decrease in growth rate can initiate metamorphosis early. Recent authors have suggested that this plasticity may be lost at some point during the larval period. We tested this hypothesis by exposing groups of tadpoles of the gray treefrog, Hyla versicolor, to dif...
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ژورنال
عنوان ژورنال: Nature
سال: 1951
ISSN: 0028-0836,1476-4687
DOI: 10.1038/167084a0