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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: The data suggest that phosphate-hemoglobin interactions are not adaptive in the sense of having been scrutinised by natural selection, but are part of a package of regulatory mechanisms reflecting phenotypic plasticity.
Abstract: 1. 1. The hemoglobin oxygen affinity of “stripped” hemolysate from Bufo marinus was sensitive to the allosteric cofactors ATP and 2,3-diphosphoglycerate which occur in toad erythrocytes. 2. 2. The affinity constants were not appreciably affected by changes in inorganic ions in the concentration range likely to be of physiological significance. 3. 3. The P 50 of toad blood of pH 7.9 and p CO 2 = 7.2 mmHg was 56.7 ± 3.1 mmHg at 30°C, with Hill's coefficient, n = 2.8. 4. 4. The P 50 was not significantly changed following 11–14 days hypoxic acclimation of the toads at p O 2 = 31 mmHg, 28°C, despite a significant rise in 2,3-DPG from 28.3 ± 3.2 to 35.1 ± 2.5 μ mol/gHb. 5. 5. These data suggest that phosphate-hemoglobin interactions are not adaptive in the sense of having been scrutinised by natural selection, but are part of a package of regulatory mechanisms reflecting phenotypic plasticity. The inherent dangers of extrapolation from molecular to physiological studies are emphasised.
6 citations
6 citations
TL;DR: Weight loss during the first 7 days of thyroxine administration suggests, under the present experimental conditions, a possible metabolic effect of the hormone.
6 citations
TL;DR: Results showed that pre-metamorphic cane toad aqueous extracts used at 1 mg/ml on MDCK cells generated cytotoxicity levels comparable to ouabain treatment (3 microM), and extracts from 2-3-month-old toadlets appeared less toxic than pre- and early metamorphic stages.
6 citations
TL;DR: The present results confirm and extend to A. brasiliana the existence of cholinergic principles in the midgut gland, probably acetylcholine and urocanylcholine, as found by Blankenship et al. (1975) in another sea here.
6 citations