Plasma and white adipose tissue lipid composition in marmots

White adipose tissue biopsies and plasma samples were obtained from hibernating yellow-bellied marmots (Marmota flaviventris) maintained in the laboratory. In addition, biopsies and plasma samples were obtained from normothermic animals in the field and laboratory. Measurement of plasma free fatty acid (FA) levels indicated that winter laboratory animals exhibited increased lipolysis. Additionally, analysis of white adipose tissue triacylglycerol revealed that the FA composition of the storage fat in animals maintained on the standard laboratory diet is remarkably simple and uniform between different adipose depots in the same animal. Three FAs (palmitic, oleic, and linoleic acids) made up greater than 95% of the total. Triene (alpha-linolenate) was found in newly captured animals, but the percentage of this FA decreased rapidly when the animals were maintained on the standard laboratory diet. Throughout the hibernation season (October to April), white adipose tissue-saturated FA percentage decreased, monoene percentage remained constant, and diene percentage increased. Analysis of plasma FA composition suggested that these animals tended to metabolize saturated FAs from stored lipid during hibernation and that dienes were mobilized briefly after the last arousal from hibernation in spring. From these observations, we hypothesize that marmots preferentially metabolize saturated fats during the hibernation period and that essential FAs of the omega 6 series tend to be metabolized more slowly than other FAs. These characteristics suggest that marmots are a valuable animal model in which to study lipid metabolism.

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Seasonal changes in hormone-sensitive and lipoprotein lipase mRNA concentrations in marmot white adipose tissue

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1992.262.2.r177 ◽

1992 ◽

Vol 262 (2) ◽

pp. R177-R181 ◽

Cited By ~ 9

Author(s):

B. E. Wilson ◽

S. Deeb ◽

G. L. Florant

Keyword(s):

Adipose Tissue ◽

Lipoprotein Lipase ◽

White Adipose Tissue ◽

Mass Gain ◽

The Body ◽

Hormone Sensitive Lipase ◽

Marmota Flaviventris ◽

Fasting Period ◽

Hormone Sensitive ◽

Clear Increase

White adipose tissue (WAT) and plasma samples were obtained from yellow-bellied marmots (Marmota flaviventris) throughout the year. Mean plasma triacylglycerol (TG), free fatty acids (FFAs), and glycerol were determined. There was a clear increase in FFAs and decrease in mean TG and glycerol during the hibernation period when animals were fasting, suggesting increased lipolysis. RNA was isolated from WAT biopsies at four times in the year: spring, summer, fall, and winter. There were significant changes in the relative levels of mRNA for lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) during the body mass cycle of the marmot. The relative levels of LPL mRNA are high during the mass gain phase of the year and that of HSL mRNA are high during the fasting period when endogenous lipid is utilized. These results suggest that the genes for LPL and HSL are regulated seasonally to control the adipose mass depot in marmots.

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Regional variations in metabolic responses of white adipose tissue to food restriction

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1994.267.6.e892 ◽

1994 ◽

Vol 267 (6) ◽

pp. E892-E899 ◽

Cited By ~ 2

Author(s):

M. C. Sugden ◽

R. M. Grimshaw ◽

H. Lall ◽

M. J. Holness

Keyword(s):

Adipose Tissue ◽

Fatty Acid ◽

White Adipose Tissue ◽

Fatty Acid Synthesis ◽

Food Restriction ◽

Glucose Utilization ◽

Acid Synthesis ◽

Anatomical Location ◽

Standard Laboratory Diet

The effects of food restriction (limited access to food for 2 h/day for 10 days) on lipoprotein lipase (LPL) activities and rates of fatty acid synthesis and glucose utilization in vivo in two superficial (interscapular and subcutaneous) and three deep abdominal white adipose tissue depots (parametrial, perirenal, and mesenteric) of adult female Wistar rats were examined before and at 2 h after a standard laboratory diet meal (5 g). Fasting LPL activities in perirenal (1.6-fold), mesenteric (5.9-fold), and subcutaneous (2.7-fold) adipose tissue, when expressed per unit of delipidated tissue, were increased in response to food restriction. This effect was retained (but not enhanced) after the meal. In contrast, muscle LPL activities were either unchanged or suppressed by food restriction. Stimulation of adipose tissue fatty acid synthesis and glucose utilization evoked by feeding in control rats was greatly enhanced by prior food restriction. There was no relationship between anatomical location and presence or absence of the response of adipose tissue LPL activity to food restriction, but the effect of food restriction to enhance the responses of fatty acid synthesis and glucose utilization to a meal was more marked in perirenal and parametrial adipose tissue than in the more superficial depots. The results thus demonstrate regional specificity in the response of adipose tissue functions to food restriction.

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Seasonal Changes in Endocannabinoid Concentrations between Active and Hibernating Marmots (Marmota flaviventris)

Journal of Biological Rhythms ◽

10.1177/0748730418777660 ◽

2018 ◽

Vol 33 (4) ◽

pp. 388-401 ◽

Cited By ~ 6

Author(s):

Emily A. Mulawa ◽

Jay S. Kirkwood ◽

Lisa M. Wolfe ◽

Samantha J. Wojda ◽

Jessica E. Prenni ◽

...

Keyword(s):

Bone Marrow ◽

Adipose Tissue ◽

Energy Metabolism ◽

Brown Adipose Tissue ◽

Cortical Bone ◽

White Adipose Tissue ◽

Endocannabinoid System ◽

Negative Consequences ◽

Marmota Flaviventris ◽

Brown Adipose

Hibernation is a naturally occurring model for studying diseases such as obesity and osteoporosis. Hibernators, marmots (Marmota flaviventris) among them, are able to nearly double their body mass by increasing fat stores prior to hibernation without the negative consequences of obesity. They are also physically inactive for extended periods of time without experiencing negative effects on the skeleton. The endocannabinoid system is involved in modulating neural signaling, circannual rhythms, behavior, appetite, thermogenesis, and bone and energy metabolism. These systems are also altered to maintain homeostasis during hibernation. This study aims to better understand the involvement of the endocannabinoid system in the regulation of physiological processes during hibernation by quantifying the seasonal variation of endocannabinoids and endocannabinoid-like ligands in both active and hibernating marmots. We hypothesized that there would be significant changes in endocannabinoid concentrations at the tissue level in marmots between active and hibernating states. Concentrations were measured in brain, serum, brown adipose tissue, white adipose tissue, bone marrow, cortical bone, and trabecular bone using microflow chromatography coupled with tandem quadrupole mass spectrometry. Significant changes were found, such as a 30-fold decrease in 2-arachidonoyl glycerol (2-AG) in cortical bone during hibernation. Many endocannabinoid and endocannabinoid-like ligands decreased in brown adipose tissue, white adipose tissue, and cortical bone, while several ligands increased in bone marrow. This result supports our hypothesis and suggests the possibility of a peripherally controlled shift in energy metabolism, reduction in bone metabolism, and suppression of the immune system during hibernation.

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Sire breed and sex effects on the fatty acid composition and content of heart, kidney, liver, adipose and muscle tissues of purebred and first-cross prime lambs

Animal Production Science ◽

10.1071/an14906 ◽

2016 ◽

Vol 56 (12) ◽

pp. 2122 ◽

Cited By ~ 11

Author(s):

A. E. O. Malau-Aduli ◽

B. W. B. Holman ◽

A. Kashani ◽

P. D. Nichols

Keyword(s):

Adipose Tissue ◽

Fatty Acid ◽

Kidney Tissue ◽

Omega 3 ◽

Tissue Concentrations ◽

Sex Effects ◽

Fa Composition ◽

Omega 6 ◽

Total Pufa ◽

Sire Breed

The present study investigated sire breed and sex effects on the fatty acid (FA) composition and content of subcutaneous adipose, Longissimus lumborum muscle, kidney, heart and liver tissues in prime lambs. Tissue samples were taken from 40 Merino ewe and wether lambs sired by Black Suffolk, Dorset, Merino and White Suffolk rams. FA proportion (% total FA) showed significant variations. The highest relative concentrations of total saturated fatty acid (SFA) were in adipose tissue, concentrations of monounsaturated fatty acids (MUFA) were highest in muscle and concentrations of two nutritionally important omega-3 long-chain (≥C20) polyunsaturated FA (LC-PUFA), namely, eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, were highest in kidney tissue (10.4% total FA), as were those of total PUFA in heart tissue. Sire breed variations in kidney for 18:3n-3, 22:6n-3, 16:0, 16:1n-7c and total omega-6 PUFA, and in muscle for 17:0, 18:3n-3 and 18:1n-7 were evident. Adipose tissue concentrations of 16:1n-9c, 17 : 0 and 16 : 0 in the heart and liver were affected by sire breed. The effect of sex on most major individual FA and totals of SFA, MUFA, omega-3 and omega-6 PUFA were, for the most part, negligible. These results suggest that consumption of lamb heart, liver and kidney can prove beneficial because of their high total PUFA composition and, in particular, concentration (mg/100 g) of key health-benefitting n-3 LC-PUFA. The fact that there were significant sire-breed variations implies that the manipulation of FA composition and content of lamb products and their associated nutritional and sensory qualities will need a deliberate breeding management that matches product goals with available sire breeds.

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