Cardiovascular function in large to small hibernators: bears to ground squirrels

Verfasser / Beitragende:
[O. Nelson, Charles Robbins]
Ort, Verlag, Jahr:
2015
Enthalten in:
Journal of Comparative Physiology B, 185/3(2015-04-01), 265-279
Format:
Artikel (online)
ID: 605514224
LEADER caa a22 4500
001 605514224
003 CHVBK
005 20210128100703.0
007 cr unu---uuuuu
008 210128e20150401xx s 000 0 eng
024 7 0 |a 10.1007/s00360-014-0881-5  |2 doi 
035 |a (NATIONALLICENCE)springer-10.1007/s00360-014-0881-5 
245 0 0 |a Cardiovascular function in large to small hibernators: bears to ground squirrels  |h [Elektronische Daten]  |c [O. Nelson, Charles Robbins] 
520 3 |a Mammalian hibernation has intrigued scientists due to extreme variations in normal seasonal physiological homeostasis. Numerous species manifest a hibernation phenotype although the characteristics of the hypometabolic state can be quite different. Ground squirrels (e.g., Sciuridae) are often considered the prototypical hibernator as individuals in this genus transition from an active, euthermic state (37°C) to a nonresponsive hibernating state where torpid body temperature commonly falls to 3-5°C. However, the hibernating state is not continuous as periodic warming and arousals occur. In contrast, the larger hibernators of genus Ursus are less hypothermic (body temperatures decline from approximately 37°-33°C), are more reactive, and cyclical arousals do not occur. Both species dramatically reduce cardiac output during hibernation from the active state (bears ~75% reduction in bears and ~97% reduction in ground squirrels), and both species demonstrate hypokinetic atrial chamber activity. However, there are several important differences in cardiac function between the two groups during hibernation. Left ventricular diastolic filling volumes and stroke volumes do not differ in bears between seasons, but increased diastolic and stroke volumes during hibernation are important contributors to cardiac output in ground squirrels. Decreased cardiac muscle mass and increased ventricular stiffness have been found in bears, whereas ground squirrels have increased cardiac muscle mass and decreased ventricular stiffness during hibernation. Molecular pathways of cardiac muscle plasticity reveal differences between the species in the modification of sarcomeric proteins such as titin and α myosin heavy chain during hibernation. The differences in hibernation character are likely to account for the alternative cardiac phenotypes and functional strategies manifested by the two species. Molecular investigation coupled with better knowledge of seasonal physiological alterations is dramatically advancing our understanding of small and large hibernators and their evolutionary differences. 
540 |a Springer-Verlag Berlin Heidelberg, 2014 
690 7 |a Cardiac function  |2 nationallicence 
690 7 |a Cardiovascular phenotype  |2 nationallicence 
690 7 |a Cardiac output  |2 nationallicence 
690 7 |a Heart rhythm  |2 nationallicence 
690 7 |a Atrial chamber  |2 nationallicence 
700 1 |a Nelson  |D O.  |u Department of Veterinary Clinical Sciences, Washington State University, 100 Grimes Way, 99164, Pullman, WA, USA  |4 aut 
700 1 |a Robbins  |D Charles  |u School of the Environment and School of Biological Sciences, Washington State University, 99164, Pullman, WA, USA  |4 aut 
773 0 |t Journal of Comparative Physiology B  |d Springer Berlin Heidelberg  |g 185/3(2015-04-01), 265-279  |x 0174-1578  |q 185:3<265  |1 2015  |2 185  |o 360 
856 4 0 |u https://doi.org/10.1007/s00360-014-0881-5  |q text/html  |z Onlinezugriff via DOI 
898 |a BK010053  |b XK010053  |c XK010000 
900 7 |a Metadata rights reserved  |b Springer special CC-BY-NC licence  |2 nationallicence 
908 |D 1  |a review-article  |2 jats 
949 |B NATIONALLICENCE  |F NATIONALLICENCE  |b NL-springer 
950 |B NATIONALLICENCE  |P 856  |E 40  |u https://doi.org/10.1007/s00360-014-0881-5  |q text/html  |z Onlinezugriff via DOI 
950 |B NATIONALLICENCE  |P 700  |E 1-  |a Nelson  |D O.  |u Department of Veterinary Clinical Sciences, Washington State University, 100 Grimes Way, 99164, Pullman, WA, USA  |4 aut 
950 |B NATIONALLICENCE  |P 700  |E 1-  |a Robbins  |D Charles  |u School of the Environment and School of Biological Sciences, Washington State University, 99164, Pullman, WA, USA  |4 aut 
950 |B NATIONALLICENCE  |P 773  |E 0-  |t Journal of Comparative Physiology B  |d Springer Berlin Heidelberg  |g 185/3(2015-04-01), 265-279  |x 0174-1578  |q 185:3<265  |1 2015  |2 185  |o 360