Circulation in Mammalian Hibernation

Lyman, Charles P.

doi:10.21236/ad0406621

Cited by 24 publications

(12 citation statements)

References 28 publications

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“…Two hours after arousal from hibernation, the percentage of TH and NPY-immunoreactive nerve profiles was reduced, but it was still higher than those of normothermic and cold control animals. This increase is consistent with reports of high peripheral vascular resistance and of increased sympathetic nerve activity during hibernation (Lyman, 1965 ;Nedergaard & Cannon, 1990). A decrease in immunoreactivity of the sympathetic markers 2 h after arousal from hibernation indicates a rapid mechanism for return of sympathetic nerve activity to normality.…”

Section: supporting

confidence: 91%

“…Food intake and gut function are suspended and renal function is reduced. Arousal is rapid and starts with an increase in heart rate, respiration and oxygen consumption, followed by a rise in body temperature and regulation of vasodilatation which leads to an increase in blood pressure and blood flow (Chatfield & Lyman, 1950 ;Lyman, 1965 ;Lyman & O'Brien, 1988).…”

Section: mentioning

confidence: 99%

See 1 more Smart Citation

Electron‐immunocytochemical studies of perivascular nerves of mesenteric and renal arteries of golden hamsters during and after arousal from hibernation

Saitongdee¹,

Milner²,

Loesch³

et al. 1999

Journal of Anatomy

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Electron immunocytochemistry was used to examine perivascular nerves of hamster mesenteric and renal arteries during hibernation and 2 h after arousal from hibernation. Vessels from cold-exposed but nonhibernating, and normothermic control hamsters were also examined. During hibernation the percentage of axon profiles in mesenteric and renal arteries that were immunopositive for markers of sympathetic nerves, tyrosine hydroxylase (TH) and neuropeptide Y (NPY), were increased 2-3 fold compared with normothermic and cold control animals. This increase was reduced markedly only 2 h after arousal from hibernation. The small percentage of nitric oxide synthase-1-positive axon profiles found in mesenteric (but not renal) arteries was also increased during hibernation and returned towards control values after arousal. In contrast, the percentage of perivascular axons immunostaining for vasoactive intestinal polypeptide (VIP), a marker for parasympathetic nerves, was reduced in mesenteric arteries during hibernation. There was no labelling of perivascular nerves for substance P in either mesenteric or renal arteries. It is suggested that the increase in percentage of TH-and NPY-immunostained perivascular nerves may account for the increased vasoconstriction associated with high vascular resistance that is known to occur during hibernation. The reduction in the percentage of axons positive for VIP in hibernating animals would contribute to this mechanism since this neuropeptide is a vasodilator.Key words : Tyrosine hydroxylase ; neuropeptide Y ; vasoactive intestinal peptide ; substance P ; nitric oxide synthase. In mammals, hibernation represents an effective strategy for surviving periods of harsh ecological conditions, a scarcity of food and adverse low temperature weather conditions. The physiological change from the normothermic condition to the state of hibernation is characterised by a decrease in metabolic rate and body temperature to below 10 mC, a reduced heart rate to below 10 beats\min, reduced respiratory rate of less than 3 breaths\min, a decrease in systemic blood pressure to about 50 mmHg, but an increase in peripheral vascular resistance (Lyman,

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Section: supporting

confidence: 91%

Section: mentioning

confidence: 99%

Electron‐immunocytochemical studies of perivascular nerves of mesenteric and renal arteries of golden hamsters during and after arousal from hibernation

Saitongdee¹,

Milner²,

Loesch³

et al. 1999

Journal of Anatomy

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show abstract

“…2). In many species, as body temperature falls the length of the skipped beats whch occur at regular intervals become prolonged (asystoles) and more frequent, with the periods of regular heart rate between them decreasing until the animals attain the slow, uniform heart rate seen in deep hibernation (Lyman, 1965. Admiiiistration of atropine …”

Section: Vagal Control Of Cardiorespiratory Function During Entrance mentioning

confidence: 99%

Physiological Society Symposium – Vagal Control: From Axolotl to Man

Milsom

Zimmer

Harris

2001

Experimental Physiology

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“…The 26 presented papers in that first meeting focused greatly on the physiology of hibernation and has set the tone for the ensuing meetings. One of the highlights of the meeting and subsequent symposium volume were the candid discussions (Lyman and Dawe 1960). Members of the hibernation community shared insight after each presentation and discussed the future directions of the field.…”

mentioning

confidence: 99%

“…The first meeting was held May 13-15, 1959 at the Massachusetts Institute of Technology Endicott House (see Table 1). The 26 presented papers in that first meeting focused greatly on the physiology of hibernation and has set the tone for the ensuing meetings.…”

mentioning

confidence: 99%