Related Papers
Horizons in Starvation Research
2012 •
Marshall D McCue
Physiological and biochemical zoology : PBZ
Previous Repeated Exposure to Food Limitation Enables Rats to Spare Lipid Stores during Prolonged Starvation
Marshall D McCue
The risk of food limitation and, ultimately, starvation dates back to the dawn of heterotrophy in animals, yet starvation remains a major factor in the regulation of modern animal populations. Researchers studying starvation more than a century ago suggested that animals subjected to sublethal periods of food limitation are somehow more tolerant of subsequent starvation events. This possibility has received little attention over the past decades, yet it is highly relevant to modern science for two reasons. First, animals in natural populations are likely to be exposed to bouts of food limitation once or more before they face prolonged starvation, during which the risk of mortality becomes imminent. Second, our current approach to studying starvation physiology in the laboratory focuses on nourished animals with no previous exposure to nutritional stress. We examined the relationship between previous exposure to food limitation and potentially adaptive physiological responses to star...
Comparative biochemistry and physiology. A, Comparative physiology
Long-term starvation in Xenopus laevis Daudin--II. Effects on several organs
1988 •
Wojciech Hanke
1. The effect of starvation for 12 months on organo-somatic indices, glycogen, protein and water contents of several organs and the Na+/K+ ratio in muscle was studied in the South African clawed toad Xenopus laevis Daudin. 2. The liver- and ovary-somatic index were reduced by 30 and 70% of the initial value after 12 months. Fat bodies had disappeared after approximately 6 months of starvation. The indices of heart and kidney were not changed. 3. Glycogen concentration of the liver, ovaries and muscle were depleted nearly totally during the first half of the experimental time, whereas glycogen in the kidney seemed to be unaffected. 4. Protein concentration increased in the liver, decreased in the muscle and remained constant in the kidney. 5. Starvation caused an increase of the water concentration of the whole animal and different organs, especially at the end of the experiment. 6. The Na+/K+ ratio of the muscle increased significantly after 6 months of starvation and reached a maxi...
Price E.R., Valencak T.G. (2012) Changes in fatty acid composition during starvation in vertebrates: mechanisms and questions. In: Comparative Physiology of Fasting, Starvation, and food limitation. Chapter 15, p. 237-256.
Changes in Fatty Acid Composition during Starvation in Vertebrates: Mechanisms and Questions
2012 •
Teresa G . Valencak
Animals often rely heavily on stored lipids as a fuel source during extended periods of fasting/starvation; this results in notable decreases in lipid content during the fast. Additionally, the composition of stored lipids often changes during periods of fasting, although the reasons for these compositional changes have not been fully explored. We examine the changes in fatty acid composition that occur during starvation through the lens of two important processes: (1) changes in the triacylglycerol to phospholipid ratio and (2) selective mobilization and oxidation of particular fatty acids. As triacylglycerols are oxidized, the ratio of triacylglycerols to phospholipids should decrease, resulting in higher overall proportions of polyunsaturated fatty acids, which are more abundant in phospholipids. Selective mobilization of fatty acids results in the preferential oxidation of short-chained and highly unsaturated fatty acids, the proportions of which should therefore decrease during starvation. In general, decreases in the triacylglycerol to phospholipid ratio appear to explain observed changes in fatty acid composition of whole animals and some tissues. On the other hand, selective mobilization of fatty acids can explain many of the compositional changes observed in adipose tissue. Together, these two processes should be considered when seeking to identify exceptional species or examples of unique lipid regulation. One notable exception is hibernating mammals, which do not exhibit standard selective mobilization patterns, possibly in order to conserve certain essential polyunsaturated fatty acids during their hibernation fast.
An Introduction to Fasting, Starvation, and Food Limitation
2012 •
Marshall D McCue
Proceedings of the Nutrition Society
Feeding, fasting and starvation: factors affecting fuel utilization
1995 •
Ian Macdonald
Endocrinology
Starvation: Early Signals, Sensors, and Sequelae
1999 •
Nancy Levin, Liza Soriano
Primates
Metabolism during starvation/dehydration stress in two species of galagos
1989 •
John Kamau
Two species of galagos (G. senegalensis moholi andG. garnettii) were subjected to dehydration and starvation stress in order to determine whether, as is common in other animals, these hypometabolic prosimians would lower their metabolic rate even further. Dehydration was confirmed by losses in body mass, a decrease in fecal water content and a rise in urine osmolality. At the height of dehydration, 20 to 25% reduction in body mass, 30 to 40% reduction in fecal water content and urine osmolality ranging from 1.8 to 3.5 Osmol kg−1 H2O, were recorded in some of the animals. Basal metabolic rate of 0.536 ml O2 (g·h)−1 inG. s. moholi and 0.302 ml O2 (g·h)−1 inG. garnettii were recorded, representing 50 to 42% reduction in metabolic rate, respectively, compared with mass specific values. In none of the tested animals did we observe significant reduction in basal metabolism during dehydration/starvation stress compared with the rates observed during the control period. Basal metabolism in the bushbabies seems to have reached the lowest level and no further adjustment is apparently possible as a strategy for energy saving during starvation and/or dehydration stress.
Endocrinology
Starvation: Early Signals, Sensors, and Sequelae 1
1999 •
Alison Strack
Journal of Experimental Biology
Behavioural, physiological and metabolic responses to long-term starvation and refeeding in a blind cave-dwelling (Proteus anguinus) and a surface-dwelling (Euproctus asper) salamander. J Exp Biol 204(Pt 2):269-281
Frédéric Hervant
