Decrease in the red cell cofactor 2,3-diphosphoglycerate increases hemoglobin oxygen affinity in the hibernating brown bear Ursus arctos

2013 ◽  
Vol 304 (1) ◽  
pp. R43-R49 ◽  
Author(s):  
Inge G. Revsbech ◽  
Hans Malte ◽  
Ole Fröbert ◽  
Alina Evans ◽  
Stéphane Blanc ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Oxygen Affinity ◽  
Brown Bear ◽  
Temperature Sensitive ◽  
Red Cell ◽  
Brown Bears ◽  
Hemoglobin Oxygen Affinity ◽  
Free Ranging ◽  
Winter Hibernation

During winter hibernation, brown bears ( Ursus arctos) reduce basal O2 consumption rate to ∼25% compared with the active state, while body temperature decreases moderately (to ∼30°C), suggesting a temperature-independent component in their metabolic depression. To establish whether changes in O2 consumption during hibernation correlate with changes in blood O2 affinity, we took blood samples from the same six individuals of hibernating and nonhibernating free-ranging brown bears during winter and summer, respectively. A single hemoglobin (Hb) component was detected in all samples, indicating no switch in Hb synthesis. O2 binding curves measured on red blood cell lysates at 30°C and 37°C showed a less temperature-sensitive O2 affinity than in other vertebrates. Furthermore, hemolysates from hibernating bears consistently showed lower cooperativity and higher O2 affinity than their summer counterparts, regardless of the temperature. We found that this increase in O2 affinity was associated with a significant decrease in the red cell Hb-cofactor 2,3-diphosphoglycerate (DPG) during hibernation to approximately half of the summer value. Experiments performed on purified Hb, to which DPG had been added to match summer and winter levels, confirmed that the low DPG content was the cause of the left shift in the Hb-O2 equilibrium curve during hibernation. Levels of plasma lactate indicated that glycolysis is not upregulated during hibernation and that metabolism is essentially aerobic. Calculations show that the increase in Hb-O2 affinity and decrease in cooperativity resulting from decreased red cell DPG may be crucial in maintaining a fairly constant tissue oxygen tension during hibernation in vivo.

scholarly journals Trichinella spp. in Wild Boars (Sus scrofa), Brown Bears (Ursus arctos), Eurasian Lynxes (Lynx lynx) and Badgers (Meles meles) in Estonia, 2007–2014

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 183
Author(s):  
Age Kärssin ◽  
Liidia Häkkinen ◽  
Annika Vilem ◽  
Pikka Jokelainen ◽  
Brian Lassen
Keyword(s):  
Sus Scrofa ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Meles Meles ◽  
Lynx Lynx ◽  
Brown Bears ◽  
Wild Boars ◽  
Infection Pressure ◽  
High Infection ◽  
Free Ranging

In this study, we summarize Trichinella findings from four wild, free-ranging host species from Estonia during 2007–2014. Trichinella spp. larvae were detected in 281 (0.9%, 95% confidence interval (CI) 0.8–1.0) of 30,566 wild boars (Sus scrofa), 63 (14.7%, 95% CI 11.6–18.3) of 429 brown bears (Ursus arctos), 59 (65.56%, 95% CI 55.3–74.8) of 90 Eurasian lynxes (Lynx lynx), and three (60.0%, 95% CI 18.2–92.7) of five badgers (Meles meles). All four European Trichinella species were detected: T. britovi in 0.7% of the wild boars, 7.2% of the brown bears, 45.6% of the lynxes, and 40.0% of the badgers; T. nativa in 0.1% of the wild boars, 5.8% of the brown bears, and 20.0% of the lynxes; T. pseudospiralis in 0.02% the wild boars; and T. spiralis in 0.03% of the wild boars and 4.4% of the lynxes. The results include the first description from Estonia of T. britovi in brown bear and badgers, T. pseudospiralis in wild boars, and T. spiralis in wild boars and lynxes. The results indicate high infection pressure in the sylvatic cycles across the years—illustrating continuous risk of spillover to domestic cycles and of transmission to humans.

scholarly journals Effects of different doses of medetomidine and tiletamine–zolazepam on the duration of induction and immobilization in free-ranging yearling brown bears (Ursus arctos)

2012 ◽  
Vol 90 (6) ◽  
pp. 753-757 ◽  
Author(s):  
Johanna Painer ◽  
Andreas Zedrosser ◽  
Jon M. Arnemo ◽  
Åsa Fahlman ◽  
Sven Brunberg ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Brown Bear ◽  
Lower Probability ◽  
Depth Of Anaesthesia ◽  
Brown Bears ◽  
Prolonged Duration ◽  
Induction Times ◽  
The Individual ◽  
Free Ranging ◽  
Different Doses

We compared anesthetic protocols with different doses of tiletamine–zolazepam (TZ) combined with medetomidine (M) for 288 yearling brown bear ( Ursus arctos L., 1758) immobilizations with the objective of finding a combination of doses that would provide fast induction with a duration of anesthesia long enough to minimize the need for administering additional drug. The duration of induction time and immobilization was dose-dependent. Increasing the M dose resulted in significantly shorter induction times and a lower probability of giving supplemental drugs. Increasing the TZ dose prolonged duration of anesthesia. For yearling brown bears in Scandinavia, captured shortly after den emergence in April and May, we recommend total dart doses of 1.0–1.66 mg M/dart, plus 62.5–125 mg TZ/dart, depending on the individual requirements for the length and depth of anaesthesia.

Sexing free-ranging brown bears Ursus arctos using hairs found in the field

1993 ◽  
Vol 2 (6) ◽  
pp. 399-403 ◽  
Author(s):  
P. TABERLET ◽  
H. MATTOCK ◽  
C. DUBOIS-PAGANON ◽  
J. BOUVET
Keyword(s):  
Ursus Arctos ◽  
Brown Bears ◽  
Free Ranging

scholarly journals The smell of success: Reproductive success related to rub behavior in brown bears

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247964
Author(s):  
Andrea T. Morehouse ◽  
Anne E. Loosen ◽  
Tabitha A. Graves ◽  
Mark S. Boyce
Keyword(s):  
Reproductive Success ◽  
Ursus Arctos ◽  
Scent Marking ◽  
Brown Bear ◽  
Parentage Analysis ◽  
Fitness Component ◽  
Brown Bears ◽  
Male And Female ◽  
Rubbing Behavior ◽  
Insight Into

Several species of bears are known to rub deliberately against trees and other objects, but little is known about why bears rub. Patterns in rubbing behavior of male and female brown bears (Ursus arctos) suggest that scent marking via rubbing functions to communicate among potential mates or competitors. Using DNA from bear hairs collected from rub objects in southwestern Alberta from 2011–2014 and existing DNA datasets from Montana and southeastern British Columbia, we determined sex and individual identity of each bear detected. Using these data, we completed a parentage analysis. From the parentage analysis and detection data, we determined the number of offspring, mates, unique rub objects where an individual was detected, and sampling occasions during which an individual was detected for each brown bear identified through our sampling methods. Using a Poisson regression, we found a positive relationship between bear rubbing behavior and reproductive success; both male and female bears with a greater number of mates and a greater number of offspring were detected at more rub objects and during more occasions. Our results suggest a fitness component to bear rubbing, indicate that rubbing is adaptive, and provide insight into a poorly understood behaviour.

scholarly journals Specific shifts in the endocannabinoid system in hibernating brown bears

2020 ◽  
Author(s):  
Christian Boyer ◽  
Laura Cussonneau ◽  
Charlotte Brun ◽  
Christiane Deval ◽  
Jean-Paul Pais de Barros ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Ursus Arctos ◽  
Mild Hypothermia ◽  
Endocannabinoid System ◽  
Fold Increase ◽  
Physiological Adaptation ◽  
Acid Oxidation ◽  
Brown Bears ◽  
Peripheral Tissues ◽  
Free Ranging

Abstract In small hibernators, global downregulation of the endocannabinoid system (ECS), which is involved in modulating neuronal signaling, feeding behavior, energy metabolism, and circannual rhythms, has been reported to possibly drive physiological adaptation to the hibernating state. We hypothesized that specific changes should occur in hibernating brown bears ( Ursus arctos ) due to specific features, including hibernation during half the year at only mild hypothermia while remaining physically inactive without drinking or eating, and the absence of arousal episodes although bears remain sensitive to external disturbances. We explored circulating lipids and the ECS in plasma and metabolically active tissues (muscle and adipose tissue), in free-ranging subadult Scandinavian brown bears when both active and hibernating. In winter bear serum, in addition to a 2-fold increase in total fatty acid concentration, we found significant changes in relative proportions of circulating fatty acids, such as a 2-fold increase in docosahexaenoic acid and a decrease in arachidonic acid. In adipose and muscle tissues of hibernating bears, we found lower concentrations of both two major ligands for endocannabinoid receptors, 2-arachidonoylglycerol (2-AG) and anandamide (AEA). Gene expression was reduced for enzymes that synthesize endocannabinoid compounds, whereas an increase was observed for catabolic enzymes. Reduction in ECS tone may promote mobilization of fat stores and favor carbohydrate metabolism in skeletal muscle of hibernating bears. Additionally, high circulating of the endocannabinoid-like compound N-oleoylethanolamide (OEA) in winter could favor lipolysis and fatty acid oxidation in peripheral tissues. We also speculated on a role of OEA in the maintenance of torpor (reduction in locomotion), while promoting the capacity of bears to sense stimuli from the environment.

scholarly journals Heart rate during hyperphagia differs between two bear species

2019 ◽  
Vol 15 (1) ◽  
pp. 20180681 ◽  
Author(s):  
Boris Fuchs ◽  
Koji Yamazaki ◽  
Alina L. Evans ◽  
Toshio Tsubota ◽  
Shinsuke Koike ◽  
...  
Keyword(s):  
Heart Rate ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Black Bear ◽  
Black Bears ◽  
Brown Bears ◽  
Fat Reserves ◽  
Generalized Additive Mixed Models ◽  
Additive Mixed Models ◽  
Increased Activity

Hyperphagia is a critical part of the yearly cycle of bears when they gain fat reserves before entering hibernation. We used heart rate as a proxy to compare the metabolic rate between the Asian black bear ( Ursus thibetanus ) in Japan and the Eurasian brown bear ( Ursus arctos ) in Sweden from summer into hibernation. In the hyperphagic period, black bears feed on fat- and carbohydrate-rich hard masts whereas brown bears feed on sugar-rich berries. Availability of hard masts has quantitative and spatial annual fluctuations, which might require increased activity and result in intraspecific stress. Using generalized additive mixed models we analysed the differences in heart rate between the two species. Black bears had decreased heart rates during summer but had doubled heart rate values throughout the hyperphagic period compared to brown bears. This letter illustrates the different physiological consequences of seasonal differences in food availability in two species of the same genus dealing with the same phenological challenge.

scholarly journals Mechanism of red cell 2,3-diphosphoglycerate increase in neonatal lambs

Blood ◽  
1983 ◽  
Vol 61 (5) ◽  
pp. 920-924 ◽  
Author(s):  
NA Noble ◽  
CA Jansen ◽  
PW Nathanielsz ◽  
KR Tanaka
Keyword(s):  
Oxygen Affinity ◽  
Glucose Consumption ◽  
Red Cell ◽  
Sequential Effects ◽  
Blood Ph ◽  
Tenfold Increase ◽  
Hemoglobin Oxygen Affinity ◽  
Ph Increase ◽  
Neonatal Lambs

Abstract The tenfold increase in red cell 2,3-diphosphoglycerate (DPG) concentration that occurs during the first 5 days of life in lambs is an important adaptation to extrauterine life. In lambs, DPG reduces hemoglobin oxygen affinity by the Bohr effect. Our data on 10 neonatal lambs suggest that the biochemical mechanism underlying this DPG increase involves the following: (1) a rise in plasma glucose from 40 to 100 mg/dl in the first 48 hr of life, which allows for increased glucose consumption in the highly glucose-permeable neonatal RBC; (2) a transitory rise in blood pH begins at birth, peaks at about 20 hr, and falls slightly; (3) the pH increase coincides with a threefold increase in RBC fructose-1,6-diphosphate (FDP) concentration due, we believe, to pH activation of phosphofructokinase; (4) glycolytic intermediates after the glyceraldehyde-3-phosphate dehydrogenase (GAPD) step do not rise in the first 24 hr of life, possibly due to insufficient inorganic phosphate (Pi), a substrate of GAPD; (5) plasma Pi increases from about 7 mg/dl at birth to 11 mg/dl at 72 hr, activates the GAPD, and FDP levels decline; and (6) the in vitro activity of the DPG synthetic enzyme, DPG mutase, is increased 12-fold in neonatal compared to adult RBC. We conclude that the postnatal rise in DPG is explained at least in part by the sequential effects of these metabolic changes.

What is the Clinical Importance of Alterations of the Hemoglobin Oxygen Affinity in Preserved Blood - Especially as Produced by Variations of Red Cell 2,3 DPG Content?

Vox Sanguinis ◽  
1978 ◽  
Vol 34 (2) ◽  
pp. 111-127 ◽  
Author(s):  
J.C. Bakker ◽  
Ernest Beutler ◽  
John A. Collins ◽  
R. Ben Dawson ◽  
Lars Garby ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
Clinical Importance ◽  
Red Cell ◽  
Hemoglobin Oxygen Affinity ◽  
2,3 Dpg

scholarly journals DISEASES AND MORTALITY IN FREE-RANGING BROWN BEAR (URSUS ARCTOS), GRAY WOLF (CANIS LUPUS), AND WOLVERINE (GULO GULO) IN SWEDEN

2005 ◽  
Vol 41 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Torsten Mörner ◽  
Hanna Eriksson ◽  
Caroline Bröjer ◽  
Kristina Nilsson ◽  
Henrik Uhlhorn ◽  
...  
Keyword(s):  
Canis Lupus ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Gray Wolf ◽  
Gulo Gulo ◽  
Free Ranging

219 MORPHOMETRIC CHARACTERIZATION OF EPIDIDYMAL AND EJACULATED SPERMATOZOA FROM BROWN BEAR (URSUS ARCTOS)

2006 ◽  
Vol 18 (2) ◽  
pp. 217 ◽  
Author(s):  
V. Garcia-Macias ◽  
F. Martinez-Pastor ◽  
M. Alvarez ◽  
P. Paz ◽  
S. Borragan ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Sperm Morphology ◽  
Present Report ◽  
Surrounding Medium ◽  
Brown Bear ◽  
Blue Component ◽  
Baseline Information ◽  
Length Width ◽  
Morphological Differences ◽  
Free Ranging

Sperm morphology is an useful characteristic for estimating potential fertility. Currently, we are obtaining baseline information on various aspects of reproduction in the brown bear (Ursus arctos) with the intention of using the knowledge to establish a germplasm bank for the species. In the present report, we describe the results obtained using assisted sperm morphology analysis (ASMA, Sperm Class Analyzer®; Microptic S.L, Barcelona, Spain) to analyze the morphological differences in epidydimal (caput, corpus, and cauda) and ejaculated brown bear spermatozoa. A post-mortem epididymal sperm sample was obtained from an adult brown bear after accidental death. The epididymides were excised, washed, and dissected into the three major segments; caput, corpus and cauda. Then multiple incisions were made in the tissue to allow migration of spermatozoa into the surrounding medium. Semen was collected by electroejaculation from five adult brown bears living in a semi-free ranging environment in the Cabarceno Park (Cantabria, Spain). Anesthesia was induced using tiletamine + zolazepan (Zoletil 100®; Virbac, Carras, France; 7 mg/kg), and ketamine (Imalgene 1000®; Rhone Merieux, Lyon, France; 2 mg/kg). The electroejaculation unit (PT Electronics®; Boring, Oregon) was connected to a 3-lateral electrode transrectal probe (26 mm in diameter, 320 mm in length). Ejaculation occurred at 6–10 V/250–300 mA. For head morphometry assessment, sperm samples were fixed in glutaraldehyde and slides were smeared and air-dried for 2 h. The samples were then stained with Diff-Quik® staining (37°C; 10 min in the red component and 15 min in the blue component). The area, perimeter, length and width, and ellipticity (length/width) of heads were measured from at least 100 spermatozoa/slide. As shown in Table 1, values obtained for each measure were similar in both epididymal and ejaculated spermatozoa. These results provide normal morphometry values for brown bear spermatozoa, a potentially useful characteristic for predicting fertility. Table 1. Head morphometry for epididymis and ejaculated bear sperm (mean ± SD) This work was supported in part by CANTUR S.A. and CICYT (CGL 2004–0278/BOS).

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