Is the polar bear (Ursus maritimus) a Hibernator?: continued studies on opioids and hibernation

@article{Bruce1990IsTP,
  title={Is the polar bear (Ursus maritimus) a Hibernator?: continued studies on opioids and hibernation},
  author={David Stewart Bruce and Nancy K. Darling and Katheleen J. Seeland and Peter R. Oeltgen and Sita P. Nilekani and Steven C. Amstrup},
  journal={Pharmacology Biochemistry and Behavior},
  year={1990},
  volume={35},
  pages={705-711}
}
Polar bear behavior and biochemistry suggest they may have the ability to hibernate year-round, even though this species is not considered to be a true hibernator. This observation, plus the discovery of a hibernation-induction trigger (HIT) in the blood of black bears, prompted the examination of polar bear blood collected throughout the year for evidence of HIT, and to determine if it displayed opioid activity, as black bear blood does. A bioassay was conducted by injecting summer 13-lined… Expand
OF HIBERNATION IN BEARS
Hibernation in the Ursidae has been extensively researched over the past 30 years. This paper reviews findings of that research in the areas of general physiology and energetics; protein, fat, andExpand
Hibernation triggers and cryogens: do they play a role in hibernation?
A survey of the literary evidence on cryogens and hibernation induction triggers is given and the results of experiments on the effect of hypothalamic or i.v. injections of opioids and plasma fromExpand
Isolation and partial characterization of an opioid-like 88 kDa hibernation-related protein.
  • N. Horton, D. Kaftani, +8 authors P. Oeltgen
  • Biology, Medicine
  • Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology
  • 1998
TLDR
It is demonstrated that both HIT-containing plasma and the synthetic alpha opioid D-Ala2-D-Leu5-enkephalin (DADLE), which mimics the activity of HIT in hibernators, extend tissue survival time of a multi-organ autoperfusion system by 3-fold. Expand
No metabolic suppression in the djungarian hamster or rat by injections of plasma from the winter-sleeping brown bear
TLDR
Plasma from winter-sleeping European brown bear was injected into Djungarian hamsters and laboratory rats to test its ability to induce changes in the body temperature and activity of the recipients and suggested that there is no universal HIT-substance in the plasma of the European Brown bear. Expand
Hibernation-Induction Trigger. I. Opioid-like Effects of Prairie Dog Plasma Albumin on Induced Contractility of Guinea Pig Ileum
TLDR
Winter samples from both species have IC50s lower than samples from summer animals, indicating greater potency of winter PAFs in suppressing guinea pig ileum contractility and therefore the presence of more opioid ligands in winter prairie dog plasma. Expand
Hibernation-Induction Trigger. II. In Vitro Effects of Prairie Dog Plasma Albumin on Mouse Vas Deferens Contractility
TLDR
The results suggest that delta opioid (HIT) is present in both species throughout the calendar year and that the induction of hibernation may involve not only levels of opioid but also dynamic interactions between endogenous opioid and its receptors. Expand
Physiology of the European brown bear (Ursus arctos arctos)
TLDR
The results reveal increases and decreases in the concentration of amino acids supporting the view that the denning bear may be even able to synthesize essential amino acids, and the analysis of the total plasma fatty acids show that there may be a trend towards a greater need of unsaturated fatty acids in theDenning bear as is the case of true hibernators. Expand
Suppression of guinea pig ileum induced contractility by plasma albumin of hibernators
TLDR
It is concluded that hibernating individuals of these species contain an HIT substance that is opioid in nature and summer animals do not; an endogenous opioid similar to leu-enkephalin may be the HIT compound or give rise to it. Expand
Circannual variations in bear plasma albumin and its opioid-like effects on guinea pig ileum
TLDR
Results support the opioid nature of the albumin-bound hibernation-induction trigger substance, that it binds to the delta opiate receptor, and that delta agonist opioid production may increase during the hibernation season. Expand
Metabolism of hepatocytes from a mammalian hibernator, Spermophilus lateralis
TLDR
This unique metabolice organization may permit energetic savings by allowing for a reduced Vb2 in deep hibernation, and an elevated VO2 during arousal to support high biosynthesis rates, thereby minimizing arousal durations and their attendant thermogenic demands. Expand
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TLDR
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TLDR
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TLDR
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TLDR
Preliminary results indicated that the bears did not suffer respiratory depression and were able to thermoregulate while immobilized and could be handled safely while under the effects of the drug and workers could readily evaluate the state of their sedation by their reactions. Expand
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