TY - JOUR
T1 - Seasonal and elevational variation in glucose and glycogen in two songbird species
AU - Sweazea, Karen L.
AU - Tsosie, Krystal S.
AU - Beckman, Elizabeth J.
AU - Benham, Phred M.
AU - Witt, Christopher C.
PY - 2020/7
Y1 - 2020/7
N2 - Birds naturally maintain high glucose concentrations in the blood and tissues, even when relying on fat to meet the metabolic demands of flight or thermogenesis. One possibility is that high glucose levels might be needed to deal with these metabolic demands. Thus, we hypothesized that birds chronically exposed to colder temperatures and higher elevations have higher circulating glucose and tissue free glucose and glycogen compared to conspecifics living at warmer temperatures and lower elevations. Adult House Sparrows (Passer domesticus) and House Finches (Haemorhous mexicanus) were captured from Phoenix, AZ (340 m elevation), and Albuquerque, NM (1600 m elevation), during the summer and winter months. We measured plasma glucose, as well as free glucose and glycogen from multiple tissues. In general, high elevation and colder temperatures were associated with higher tissue glycogen and higher free glucose concentrations in the brain. These findings indicate that glucose and glycogen are subject to seasonal phenotypic flexibility as well as geographic variations that may relate to local food availability and abundance.
AB - Birds naturally maintain high glucose concentrations in the blood and tissues, even when relying on fat to meet the metabolic demands of flight or thermogenesis. One possibility is that high glucose levels might be needed to deal with these metabolic demands. Thus, we hypothesized that birds chronically exposed to colder temperatures and higher elevations have higher circulating glucose and tissue free glucose and glycogen compared to conspecifics living at warmer temperatures and lower elevations. Adult House Sparrows (Passer domesticus) and House Finches (Haemorhous mexicanus) were captured from Phoenix, AZ (340 m elevation), and Albuquerque, NM (1600 m elevation), during the summer and winter months. We measured plasma glucose, as well as free glucose and glycogen from multiple tissues. In general, high elevation and colder temperatures were associated with higher tissue glycogen and higher free glucose concentrations in the brain. These findings indicate that glucose and glycogen are subject to seasonal phenotypic flexibility as well as geographic variations that may relate to local food availability and abundance.
KW - Aves
KW - Elevation
KW - Glucose
KW - Glycogen
KW - Seasonality
UR - http://www.scopus.com/inward/record.url?scp=85083401849&partnerID=8YFLogxK
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U2 - 10.1016/j.cbpa.2020.110703
DO - 10.1016/j.cbpa.2020.110703
M3 - Article
C2 - 32283178
AN - SCOPUS:85083401849
VL - 245
JO - Comparative biochemistry and physiology. Part A, Molecular & integrative physiology
JF - Comparative biochemistry and physiology. Part A, Molecular & integrative physiology
SN - 1095-6433
M1 - 110703
ER -