Body temperature and behaviour of golden hamsters (Mesocricetus auratus) and ground squirrels (Spermophilus tridecemlineatus) in a thermal gradient

1995 ◽  
Vol 177 (6) ◽  
Author(s):  
R. Refinetti
Keyword(s):  
Body Temperature ◽  
Thermal Gradient ◽  
Mesocricetus Auratus ◽  
Ground Squirrels ◽  
Spermophilus Tridecemlineatus ◽  
Golden Hamsters

scholarly journals Circulation and metabolic rates in a natural hibernator: an integrative physiological model

2010 ◽  
Vol 299 (6) ◽  
pp. R1478-R1488 ◽  
Author(s):  
Marshall Hampton ◽  
Bethany T. Nelson ◽  
Matthew T. Andrews
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Circulatory System ◽  
Physiological Model ◽  
Ground Squirrels ◽  
Metabolic Rates ◽  
Spermophilus Tridecemlineatus ◽  
Brown Adipose ◽  
Core Body

Small hibernating mammals show regular oscillations in their heart rate and body temperature throughout the winter. Long periods of torpor are abruptly interrupted by arousals with heart rates that rapidly increase from 5 beats/min to over 400 beats/min and body temperatures that increase by ∼30°C only to drop back into the hypothermic torpid state within hours. Surgically implanted transmitters were used to obtain high-resolution electrocardiogram and body temperature data from hibernating thirteen-lined ground squirrels ( Spermophilus tridecemlineatus ). These data were used to construct a model of the circulatory system to gain greater understanding of these rapid and extreme changes in physiology. Our model provides estimates of metabolic rates during the torpor-arousal cycles in different model compartments that would be difficult to measure directly. In the compartment that models the more metabolically active tissues and organs (heart, brain, liver, and brown adipose tissue) the peak metabolic rate occurs at a core body temperature of 19°C approximately midway through an arousal. The peak metabolic rate of the active tissues is nine times the normothermic rate after the arousal is complete. For the overall metabolic rate in all tissues, the peak-to-resting ratio is five. This value is high for a rodent, which provides evidence for the hypothesis that the arousal from torpor is limited by the capabilities of the cardiovascular system.

scholarly journals Local Cerebral Blood Flow during Hibernation, a Model of Natural Tolerance to “Cerebral Ischemia”

1994 ◽  
Vol 14 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Kai U. Frerichs ◽  
Charles Kennedy ◽  
Louis Sokoloff ◽  
John M. Hallenbeck
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Ischemia ◽  
Body Temperature ◽  
Physiological State ◽  
Ground Squirrels ◽  
Control Group ◽  
Spermophilus Tridecemlineatus ◽  
Destructive Processes ◽  
Natural Tolerance

The breakdown of cellular homeostasis and progressive neuronal destruction in cerebral ischemia appears to be mediated by a complex network of causes that are intricately interrelated. We have investigated a physiological state existing normally in nature in which mammals appear to tolerate the ordinarily detrimental effects of ischemia with reduced oxygen availability and to resist activation of self-destructive processes, i.e., mammalian hibernation. Ground squirrels (Spermophilus tridecemlineatus) were chronically implanted with arterial and venous catheters and telemetry devices for electroencephalography, electrocardiography, and monitoring of body temperature. The animals were placed in an environmental chamber at an ambient temperature of 5°C. Entrance into hibernation was characterized by a drop in heart rate followed by a gradual decline in body temperature and an isoelectric electroencephalogram. Cold-adapted active animals that were not hibernating served as controls. Cerebral blood flow (CBF) was measured in both groups with the autoradiographic [14C]iodoantipyrine method. Mean (±SD) mass-weighted CBF in the brain as a whole was 62 ± 16 ml/100 g/min (n = 4) in the control group but was reduced to ischemic levels, 7 ± 4 ml/100 g/min (n = 4), in the hibernating animals (p < 0.001). No neuropathological changes were found in similarly hibernating animals aroused from hibernation. Hibernation appears to be actively regulated, and hormonal factors may be involved. The identification and characterization of such factors and of the mechanisms used by hibernating species to increase ischemic tolerance and to blunt the destructive effects of ischemia may enable us to prevent or minimize the loss of homeostatic control during and after cerebral ischemia in other species.

scholarly journals Topical treatment of experimental cutaneous leishmaniasis in golden hamster (Mesocricetus auratus) with formulations containing pentamidine

2017 ◽  
Vol 47 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Claudia Dantas COMANDOLLI-WYREPKOWSKI ◽  
Iryna GRAFOVA ◽  
Maricleide de Farias NAIFF ◽  
Maurizio AVELLA ◽  
Gennaro GENTILE ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Topical Treatment ◽  
Usnic Acid ◽  
Parasite Burden ◽  
Experimental Treatment ◽  
Mesocricetus Auratus ◽  
Current Treatment ◽  
Tissue Samples ◽  
Golden Hamsters ◽  
Pentamidine Isethionate

ABSTRACT Current treatment of cutaneous leishmaniasis (CL) relies mainly on pentavalent antimonials salts and second-line drugs include pentamidine and amphotericin B, but these therapies have side effects and require parenteral administration. The aim of this work was to evaluate the topical formulations containing pentamidine isethionate (PI) in the experimental treatment of cutaneous leishmaniasis (CL). Golden hamsters (Mesocricetus auratus) were infected in the nose with Leishmania (Leishmania) amazonensis. Six treatment groups received different topical treatments of anhydrous or hydrating emulsions, for a maximum of 10 days, with an application of 50 mg day-1. After treatment tissue samples of lesions were evaluated by histology, transmission electron microscopy and biopsy cultivation. Compared with untreated group, topical treatment with hydrating emulsion with 10% PI and usnic acid (ACE5AU) showed significantly decrease in volume lesion (P= 0.028) on 20th day after the end of the treatment with reduction of 27.37%. Topical treatment with anhydrous emulsion with 10% PI and usnic acid (ACPU) reduces parasite burden in Golden hamsters. This study demonstrated the potential of topical treatment to reduce the number of parasites that could be combined with others drugs and to have a faster and more effective treatment of cutaneous leishmaniasis.

Pineal melatonin in hibernating and aroused golden hamsters (Mesocricetus auratus)

1984 ◽  
Vol 77 (4) ◽  
pp. 759-762 ◽  
Author(s):  
Jiří Vaněček ◽  
Ladislav Janský ◽  
Helena Illnerová ◽  
Klaus Hoffmann
Keyword(s):  
Mesocricetus Auratus ◽  
Pineal Melatonin ◽  
Golden Hamsters
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