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Toad
About: Toad is a research topic. Over the lifetime, 1624 publications have been published within this topic receiving 28732 citations.
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TL;DR: Findings provide strong, albeit indirect, evidence that actin microfilaments play a functional role in the hormone-induced increase in water permeability in the toad urinary bladder.
Abstract: Vasopressin increases the water permeability of the apical membrane of the granular epithelial cells of the toad urinary bladder. Cytochalasin B inhibits this action of the hormone, indicating that microfilaments may play a role in the water permeability response. We have extended previous functional studies with cytochalasin B and have demonstrated that dihydrocytochalasin B, a more specific inhibitor of actin filament elongation, similarly diminishes the hydrosmotic response to vasopressin. Biochemical studies of isolated epithelial cells indicate that an actin-like protein accounts for about 10% of the soluble protein of the epithelium. Morphological studies of whole toad bladders incubated with heavy meromyosin conclusively demonstrate that actin is a component of the epithelial cells and that actin-containing filaments are associated with both plasma membranes and cytoplasmic organelle membranes. Taken together, these findings provide strong, albeit indirect, evidence that actin microfilaments play a functional role in the hormone-induced increase in water permeability in the toad urinary bladder.
45 citations
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45 citations
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45 citations
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TL;DR: A short loop feedback system has been proposed in which arginine vasopressin itself stimulates its antagonist PGE2 in collecting duct epithelial cells, and the mechanism of the antagonistic action of PGE on vasopressingin-induced changes in water excretion is still controversial.
44 citations