Some physiological and biochemical features of starvation and refeeding in small wild rodents (Microtinae)

Physiological condition of bank voles ( Myodes glareolus ) during the increase and decline phases of the population cycle

“…Our bank voles did not appear to be in negative energy balance, as several variables known to respond to 4-24 h of fasting in voles (leukocyte count, glucose, free FA and glycerol levels, AST and CK activities, liver glycogen and TAG contents; Mosin, 1982;Nagy and Pistole, 1988;Mustonen et al, 2008Mustonen et al, , 2012 remained unchanged during the decline phase. Food scarcity can also reduce fat deposition (Voltura and Wunder, 1998), but the WAT and BAT masses were higher in the spring of the decline phase.…”

Physiological condition of bank voles ( Myodes glareolus ) during the increase and decline phases of the population cycle

“…Our bank voles did not appear to be in negative energy balance, as several variables known to respond to 4-24 h of fasting in voles (leukocyte count, glucose, free FA and glycerol levels, AST and CK activities, liver glycogen and TAG contents; Mosin, 1982;Nagy and Pistole, 1988;Mustonen et al, 2008Mustonen et al, , 2012 remained unchanged during the decline phase. Food scarcity can also reduce fat deposition (Voltura and Wunder, 1998), but the WAT and BAT masses were higher in the spring of the decline phase.…”

De novo lipogenesis is suppressed during fasting but upregulated at population decline in cyclic voles

“…4,5,19 DNL exacerbates steatosis in humans 6 but not in voles, which may be related to the different availability of carbohydrate-based substrates. 1,2,4,22 Another major difference is insulin sensitivity: when hepatic TAG accumulate in lean fasted animals, they do not cause hepatic insulin resistance that is a characteristic of NAFLD patients. 23 While the vole model is not fully comparable to NAFLD, its benefits are the very rapid accumulation of TAG and the modification of hepatic FA profile independent of DNL.…”

“…18 However, as these PUFA decrease in vole livers during fasting, 4,5 similar to FA manifestations of NAFLD patients, 19 this hypothesis seems implausible. A more convincing explanation for the suppression of DNL derives from the observations that fasted voles also experience a depletion of liver glycogen stores 1,2,4 with consequent hypoglycemia 1 and a lack of carbohydrate-based substrates (i.e. glucose 20 ) for DNL.…”

Integrative Physiology of Fasting

“…Fasts of 5, 6, 12, and 20 months significantly reduced liver glycogen, respectively, for the eel Anguilla anguilla (by 43%), the lungfishes P. annectens and P. aethiopicus (by 40%), and the anurans Xenopus laevis (by 87%) and Rana esculenta (by 95%) (221,291,318,375). In contrast, after 10 days of fasting, the mudskipper (195,329,383,436).…”

“…Figure 5 Variation in glycogen depletion with fasting is illustrated with the relative change in liver glycogen as a function of days postfeeding for the mudskipper Boleophthalmus boddaerti, sturgeon Acipenser naccarii, bats Artibeus lituratus and A. jamaicensis (combined data), and vole Clethrionomys rufocanus. Figure drawn, with permission, from data provided in(195,329,383,436).…”

Physiological condition of bank voles ( Myodes glareolus ) during the increase and decline phases of the population cycle

“…Our bank voles did not appear to be in negative energy balance, as several variables known to respond to 4-24 h of fasting in voles (leukocyte count, glucose, free FA and glycerol levels, AST and CK activities, liver glycogen and TAG contents; Mosin, 1982;Nagy and Pistole, 1988;Mustonen et al, 2008Mustonen et al, , 2012 remained unchanged during the decline phase. Food scarcity can also reduce fat deposition (Voltura and Wunder, 1998), but the WAT and BAT masses were higher in the spring of the decline phase.…”

De novo lipogenesis is suppressed during fasting but upregulated at population decline in cyclic voles

“…4,5,19 DNL exacerbates steatosis in humans 6 but not in voles, which may be related to the different availability of carbohydrate-based substrates. 1,2,4,22 Another major difference is insulin sensitivity: when hepatic TAG accumulate in lean fasted animals, they do not cause hepatic insulin resistance that is a characteristic of NAFLD patients. 23 While the vole model is not fully comparable to NAFLD, its benefits are the very rapid accumulation of TAG and the modification of hepatic FA profile independent of DNL.…”

“…18 However, as these PUFA decrease in vole livers during fasting, 4,5 similar to FA manifestations of NAFLD patients, 19 this hypothesis seems implausible. A more convincing explanation for the suppression of DNL derives from the observations that fasted voles also experience a depletion of liver glycogen stores 1,2,4 with consequent hypoglycemia 1 and a lack of carbohydrate-based substrates (i.e. glucose 20 ) for DNL.…”

Integrative Physiology of Fasting

“…Fasts of 5, 6, 12, and 20 months significantly reduced liver glycogen, respectively, for the eel Anguilla anguilla (by 43%), the lungfishes P. annectens and P. aethiopicus (by 40%), and the anurans Xenopus laevis (by 87%) and Rana esculenta (by 95%) (221,291,318,375). In contrast, after 10 days of fasting, the mudskipper (195,329,383,436).…”

“…Figure 5 Variation in glycogen depletion with fasting is illustrated with the relative change in liver glycogen as a function of days postfeeding for the mudskipper Boleophthalmus boddaerti, sturgeon Acipenser naccarii, bats Artibeus lituratus and A. jamaicensis (combined data), and vole Clethrionomys rufocanus. Figure drawn, with permission, from data provided in(195,329,383,436).…”

Physiological condition of bank voles ( Myodes glareolus ) during the increase and decline phases of the population cycle

“…Our bank voles did not appear to be in negative energy balance, as several variables known to respond to 4-24 h of fasting in voles (leukocyte count, glucose, free FA and glycerol levels, AST and CK activities, liver glycogen and TAG contents; Mosin, 1982;Nagy and Pistole, 1988;Mustonen et al, 2008Mustonen et al, , 2012 remained unchanged during the decline phase. Food scarcity can also reduce fat deposition (Voltura and Wunder, 1998), but the WAT and BAT masses were higher in the spring of the decline phase.…”

De novo lipogenesis is suppressed during fasting but upregulated at population decline in cyclic voles

“…4,5,19 DNL exacerbates steatosis in humans 6 but not in voles, which may be related to the different availability of carbohydrate-based substrates. 1,2,4,22 Another major difference is insulin sensitivity: when hepatic TAG accumulate in lean fasted animals, they do not cause hepatic insulin resistance that is a characteristic of NAFLD patients. 23 While the vole model is not fully comparable to NAFLD, its benefits are the very rapid accumulation of TAG and the modification of hepatic FA profile independent of DNL.…”

“…18 However, as these PUFA decrease in vole livers during fasting, 4,5 similar to FA manifestations of NAFLD patients, 19 this hypothesis seems implausible. A more convincing explanation for the suppression of DNL derives from the observations that fasted voles also experience a depletion of liver glycogen stores 1,2,4 with consequent hypoglycemia 1 and a lack of carbohydrate-based substrates (i.e. glucose 20 ) for DNL.…”

Integrative Physiology of Fasting

“…Fasts of 5, 6, 12, and 20 months significantly reduced liver glycogen, respectively, for the eel Anguilla anguilla (by 43%), the lungfishes P. annectens and P. aethiopicus (by 40%), and the anurans Xenopus laevis (by 87%) and Rana esculenta (by 95%) (221,291,318,375). In contrast, after 10 days of fasting, the mudskipper (195,329,383,436).…”

“…Figure 5 Variation in glycogen depletion with fasting is illustrated with the relative change in liver glycogen as a function of days postfeeding for the mudskipper Boleophthalmus boddaerti, sturgeon Acipenser naccarii, bats Artibeus lituratus and A. jamaicensis (combined data), and vole Clethrionomys rufocanus. Figure drawn, with permission, from data provided in(195,329,383,436).…”