Gluconeogenesis in a carnivorous bird (black vulture)

Migliorini, RH; Linder, Christian; Moura, JL; Veiga, J. L.

doi:10.1152/ajplegacy.1973.225.6.1389

Cited by 83 publications

(33 citation statements)

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“…However, when cats were given high (700 g/kg) and low (170 g/kg) crude protein diets, there was little adaptation in the activities of the aminotransferases of general N metabolism to dietary protein (Rogers et al 1977). This lack of enzymic adaptation in cats was similar to that reported in other carnivorous species such as trout (Cowey et al 1981), alligators (Coulson & Hernandez, 1983), vultures (Migliorini et al 1973), and barn owls (Myers & Klasing, 1999).…”

Section: High Protein Requirement and Amino Acid Metabolismsupporting

confidence: 68%

Idiosyncratic nutrient requirements of cats appear to be diet-induced evolutionary adaptations

Morris

2002

NRR

135

147

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Cats have obligatory requirements for dietary nutrients that are not essential for other mammals. The present review relates these idiosyncratic nutritional requirements to activities of enzymes involved in the metabolic pathways of these nutrients. The high protein requirement of cats is a consequence of the lack of regulation of the aminotransferases of dispensable N metabolism and of the urea cycle enzymes. The dietary requirements for taurine and arginine are consequences of low activities of two enzymes in the pathways of synthesis that have a negative multiplicative effect on the rate of synthesis. Cats have obligatory dietary requirements for vitamin D and niacin which are the result of high activities of enzymes that catabolise precursors of these vitamins to other compounds. The dietary requirement for pre-formed vitamin A appears to result from deletion of enzymes required for cleavage and oxidation of carotenoids. The n-3 polyunsaturated fatty acids (PUFA) requirements have not been defined but low activities of desaturase enzymes indicate that cats may have a dietary need for pre-formed PUFA in addition to those needed by other animals to maintain normal plasma concentrations. The nutrient requirements of domestic cats support the thesis that their idiosyncratic requirements arose from evolutionary pressures arising from a rigorous diet of animal tissue. These pressures may have favoured energy conservation through deletion of redundant enzymes and modification of enzyme activities to result in metabolites more suited to the cat's metabolism. However, this retrospective viewpoint allows only recognition of association rather than cause and effect.

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Section: High Protein Requirement and Amino Acid Metabolismsupporting

confidence: 68%

Idiosyncratic nutrient requirements of cats appear to be diet-induced evolutionary adaptations

Morris

2002

NRR

135

147

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“…Migliorini et al, 1973). Thus, the limiting factor in diet SF might be not the excess of protein but the lack of carbohydrate.…”

Section: Discussion Prediction 1 -Nestlings and Adults Fail To Thrivementioning

confidence: 99%

Low plasticity in digestive physiology constrains feeding ecology in diet specialist, zebra finch (Taeniopygia guttata)

Brzęk

Lessner

Caviedes‐Vidal

et al. 2010

Journal of Experimental Biology

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SUMMARYIt can be hypothesized that species with a wide or variable food niche are able to adjust their digestive physiology to current food type. In diet specialists, however, the capacity for such presumably costly plasticity is not necessary and flexibility of digestive physiology should be lower. Recently, we found that ontogenetic changes in the activity of digestive enzymes in house sparrow, a species that gradually consumes more carbohydrates during ontogeny, are strongly modified by diet composition. In the present study we examined digestive flexibility of nestling and adult zebra finches, typical diet specialists that consume only seeds after hatching. Both adult and nestling zebra finches could not thrive on a protein-rich and carbohydrate-free diet that supported normal development of young house sparrows. Mass-specific activity of intestinal carbohydrases (maltase and sucrase) was not elevated by higher diet carbohydrate content in both nestling and adult birds. Mass-specific activity of maltase changed less during ontogenetic development in zebra finch than in house sparrow. We conclude that the digestive physiology of zebra finch is adapted to process carbohydrate-rich food after hatching and is much less flexible than in house sparrow. We hypothesize that this difference might reflect the lack of a diet switch during ontogeny or result from high specialization to a narrow diet niche.

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“…Related studies have shown that, after a period of experimental fasting, glucose levels remained steady in Black Vultures (Coragyps atratus) [35] and Herring Gulls (Larus argentatus) [25], or even increased in Common Buzzards (Buteo buteo) [16]. Such differences could indicate different abilities among wild bird species to survive under conditions of food deprivation.…”

Section: Reliance On Nutritional Statementioning

confidence: 98%

“…Available information indicates that the values of some blood parameters can vary according to the nutritional state [15,16,32,35,53] and/or the circadian rhythm [17]. Changes in the activity of some plasma enzymes as a result of the exposure of birds of prey to environmental toxicants have been also reported [24].…”

Section: Introductionmentioning

confidence: 99%

Factors affecting plasma chemistry values of the Spanish Imperial Eagle, Aquila adalberti

Ferrer¹,

Dobado‐Berrios²

1998

Comparative Biochemistry and Physiology Part A: Molecular &

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Studies in endangered raptors have given reference values for some blood constituents of metabolic, veterinary, ecological and/or taxonomic interest. However, the variations in such values with physiological and external factors are poorly known. In the present study, the influence of sex, age, nutritional state and local environment was tested on up to 19 plasma variables in the Spanish Imperial Eagle (Aquila adalberti ). Our results showed that differences between sexes were not significant for any of the studied parameters. However, age had a significant effect on a number of metabolites, inorganic ions and enzyme activities. In particular, age-related differences in glucose, triglyceride, lactate dehydrogenase, creatine phosphokinase and creatinine values between chick and (sub)adult eagles were found. In addition, some metabolic responses of subadult birds to fasting and refeeding were quite similar to those found in other raptors. Finally, nestlings inhabiting different geographic areas also differed in relation to the values of several plasma parameters, those dissimilarities probably accounting for quantitative and qualitative differences in their respective diets.

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Gluconeogenesis in a carnivorous bird (black vulture)

Cited by 83 publications

References 0 publications

Idiosyncratic nutrient requirements of cats appear to be diet-induced evolutionary adaptations

Idiosyncratic nutrient requirements of cats appear to be diet-induced evolutionary adaptations

Low plasticity in digestive physiology constrains feeding ecology in diet specialist, zebra finch (Taeniopygia guttata)

Factors affecting plasma chemistry values of the Spanish Imperial Eagle, Aquila adalberti

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