Influence of animal hibernation on the development of mycoses

Sharapov, V. M.

doi:10.1007/bf00436516

Cited by 11 publications

(2 citation statements)

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“…As lowering Tb brings about dysfunction of various cells and organs, such as heart and brain, hibernators are required to develop a capacity for maintaining regulated functions at potentially lethal low Tb during hiberna-tion. It has already been shown that during hibernation, organisms are protected not only from hypothermia (Hochachka, 1986) but also from ischemia (Frerichs and Hallenbeck, 1998), muscle disuse (Harlow et al, 2001), bacterial infection (Sharapov, 1983), and tumorigenesis (Kemper and Ruben, 1982), suggesting that hibernation is a unique physiological adaptation for preventing lethal damage and diseases caused by various harmful events. Such an adaptation can be assumed to be accomplished prior to the onset of and sustained during hibernation because central and peripheral organs would rapidly lose functions at low Tb if the adaptation were not accomplished in advance.…”

Section: Introductionmentioning

confidence: 99%

Circannual Control of Hibernation by HP Complex in the Brain

Kondo

Sekijima

Kondo

et al. 2006

Cell

117

123

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Seasonal hibernation in mammals is under a unique adaptation system that protects organisms from various harmful events, such as lowering of body temperature (Tb), during hibernation. However, the precise factors controlling hibernation remain unknown. We have previously demonstrated a decrease in hibernation-specific protein (HP) complex in the blood of chipmunks during hibernation. Here, HP is identified as a candidate hormone for hibernation. In chipmunks kept in constant cold and darkness, HP is regulated by an individual free-running circannual rhythm that correlates with hibernation. The level of HP complex in the brain increases coincident with the onset of hibernation. Such HP regulation proceeds independently of Tb changes in constant warmth, and Tb decreases only when brain HP is increased in the cold. Blocking brain HP activity using an antibody decreases the duration of hibernation. We suggest that HP, a target of endogenously generated circannual rhythm, carries hormonal signals essential for hibernation to the brain.

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Section: Introductionmentioning

confidence: 99%

Circannual Control of Hibernation by HP Complex in the Brain

Kondo

Sekijima

Kondo

et al. 2006

Cell

117

123

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“…Regarding feeding strategy, chipmunks and hamsters are food-storing, whereas ground squirrels, marmots and bears are fat accumulating ( Vander wall, 1990 ; Humphries et al, 2003 ). Besides the physiology and behavioral ecology of hibernation, for example, resistance to adverse factors including fungi, viruses and radiation have been well-studied ( Torke and Twente, 1977 ; Sharapov, 1984 ; Schwartz et al, 2015 ; Puspitasari et al, 2021 ). Understanding the systems that regulate seasonal switching is very interesting and has long been the subject of research on hibernating animals (for example, ground squirrel: Yurisova and Polenov (1979) ; Ren et al (2022) , hamster; Bartness and Wade (1985) ; Garidou et al (2003) , bear; Fedrov et al (2014) , bat; Callard et al (1983) .…”

Section: Introductionmentioning

confidence: 99%

Differential AMPK-mediated metabolic regulation observed in hibernation-style polymorphisms in Siberian chipmunks

Kamata,

Yamada,

Sekijima

2023

Front. Physiol.

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Hibernation is a unique physiological phenomenon allowing extreme hypothermia in endothermic mammals. Hypometabolism and hypothermia tolerance in hibernating animals have been investigated with particular interest; recently, studies of cultured cells and manipulation of the nervous system have made it possible to reproduce physiological states related to hypothermia induction. However, much remains unknown about the periodic regulation of hibernation. In particular, the physiological mechanisms facilitating the switch from an active state to a hibernation period, including behavioral changes and the acquisition of hypothermia tolerance remain to be elucidated. AMPK is a protein known to play a central role not only in feeding behavior but also in metabolic regulation in response to starvation. Our previous research has revealed that chipmunks activate AMPK in the brain during hibernation. However, whether AMPK is activated during winter in non-hibernating animals is unknown. Previous comparative studies between hibernating and non-hibernating animals have often been conducted between different species, consequently it has been impossible to account for the effects of phylogenetic differences. Our long-term monitoring of siberian chipmunks, has revealed intraspecific variation between those individuals that hibernate annually and those that never become hypothermic. Apparent differences were found between hibernating and non-hibernating types with seasonal changes in lifespan and blood HP levels. By comparing seasonal changes in AMPK activity between these polymorphisms, we clarified the relationship between hibernation and AMPK regulation. In hibernating types, phosphorylation of p-AMPK and p-ACC was enhanced throughout the brain during hibernation, indicating that AMPK-mediated metabolic regulation is activated. In non-hibernating types, AMPK and ACC were not seasonally activated. In addition, AMPK activation in the hypothalamus had already begun during high Tb before hibernation. Changes in AMPK activity in the brain during hibernation may be driven by circannual rhythms, suggesting a hibernation-regulatory mechanism involving AMPK activation independent of Tb. The differences in brain AMPK regulation between hibernators and non-hibernators revealed in this study were based on a single species thus did not involve phylogenetic differences, thereby supporting the importance of brain temperature-independent AMPK activation in regulating seasonal metabolism in hibernating animals.

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Veterinary Mycology

Lehmann

1996

Human and Animal Relationships

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Influence of animal hibernation on the development of mycoses

Cited by 11 publications

References 5 publications

Circannual Control of Hibernation by HP Complex in the Brain

Circannual Control of Hibernation by HP Complex in the Brain

Differential AMPK-mediated metabolic regulation observed in hibernation-style polymorphisms in Siberian chipmunks

Veterinary Mycology

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