title: Shallow hypothermia depends on the level of fatty acid unsaturation in adipose and liver tissues in a tropical heterothermic primate.
abstract: Optimal levels of unsaturated fatty acids have positive impacts on the use of prolonged bouts of hypothermia in mammalian hibernators, which generally have to face low winter ambient temperatures. Unsaturated fatty acids can maintain the fluidity of fat and membrane phospholipids at low body temperatures. However, less attention has been paid to their role in the regulation of shallow hypothermia, and in tropical species, which may be challenged more by seasonal energetic and/or water shortages than by low temperatures. The present study assessed the relationship between the fatty acids content of white adipose and liver tissues and the expression of shallow hypothermia in a tropical heterothermic primate, the gray mouse lemur (Microcebus murinus). The adipose tissue is the main tissue for fat storage and the liver is involved in lipid metabolism, so both tissues were expected to influence hypothermia dependence on fatty acids. As mouse lemurs largely avoid deep hypothermia (i.e. torpor) use under standard captive conditions, the expression of hypothermia was triggered by food-restricting experimental animals. Hypothermia depth increased with time, with a stronger increase for individuals that exhibited higher contents of unsaturated fatty acids suggesting that they were more flexible in their use of hypothermia. However these same animals delayed the use of long hypothermia bouts relative to individuals with a higher level of saturated fatty acids. This study evidences for the first time that body fatty acids unsaturation levels influence the regulation of body temperature not only in cold-exposed hibernators but also in tropical, facultative heterotherms.
authors: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d׳Histoire Naturelle, 1 avenue du Petit Château, 91800 Brunoy, France.
authors: Pauline
authors: P
authors: Vuarin
authors: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d׳Histoire Naturelle, 1 avenue du Petit Château, 91800 Brunoy, France.
authors: Pierre-Yves
authors: PY
authors: Henry
authors: PG Consulting, 13 Villa Bellevue, 91440 Bures sur Yvette, France.
authors: Philippe
authors: P
authors: Guesnet
authors: Institut National de la Recherche Agronomique, Département Alimentation Humaine, Domaine de Vilvert, bât. 230, Nurélice UR 909, 78352 Jouy-en-Josas, France.
authors: Jean-Marc
authors: JM
authors: Alessandri
authors: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d׳Histoire Naturelle, 1 avenue du Petit Château, 91800 Brunoy, France.
authors: Fabienne
authors: F
authors: Aujard
authors: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d׳Histoire Naturelle, 1 avenue du Petit Château, 91800 Brunoy, France.
authors: Martine
authors: M
authors: Perret
authors: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d׳Histoire Naturelle, 1 avenue du Petit Château, 91800 Brunoy, France. Electronic address: pifferi@mnhn.fr.
authors: Fabien
authors: F
authors: Pifferi
mesh_terms: D052436:Adipose Tissue, White / Q000378:metabolism*; D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology; D031204:Caloric Restriction; D016565:Cheirogaleidae / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism*; D007035:Hypothermia / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*
chemical_list: D005227:Fatty Acids
keywords: Adipose tissue; Body temperature; Heterothermic primate; Liver; Shallow hypothermia; Unsaturated fatty acids