Physiological adaptations to prolonged fasting in the overwintering striped skunk (Mephitis mephitis)

Comp Biochem Physiol A Mol Integr Physiol. 2013 Dec;166(4):555-63. doi: 10.1016/j.cbpa.2013.08.008. Epub 2013 Aug 24.

Abstract

Wintertime physiology of captive striped skunks (Mephitis mephitis) in response to cold ambient temperature (Ta) and fasting was investigated with body temperature (Tb) and activity recordings and analyses of hematology, plasma biochemistry and tissue fatty acids (FA). After 105 days of food deprivation, the skunks were in phase II of fasting indicated by the elevated plasma nonesterified FA and glycerol but no accumulation of nitrogen end products. Shorter-chain saturated and monounsaturated FA together with C18-20 n-3 polyunsaturated FA were preferentially mobilized. Individual amino acids responded to fasting in a complex manner, while essential and nonessential amino acid sums remained stable. Increases in hemoglobin and hematocrit suggested dehydration. The activity levels were lower in mid-January-early March, and the activity bouts were mostly displayed between 17:00-23:00 h. Daily torpor was observed in two females with 29 and 46 bouts. The deepest torpor (Tb<31 °C) occurred between dawn and early afternoon and lasted for 3.3 ± 0.18 h. The average minimum Tb was 29.2 ± 0.15 °C and the lowest recorded Tb was 25.8 °C. There was significant relation between the average 24-h Tb and Ta. Increases in wintertime Ta, as predicted by climate change scenarios, could influence torpor patterns in the species.

Keywords: AA; ALT; ANOVA; AST; BM; BMI; Body temperature; CBC; CK; EDTA; FA; Fatty acids; Hematology; IM; MUFA; Mephitis mephitis; PCA; PUFA; SC; SFA; Striped skunk; T(a); T(b); T(n); Torpor; U/C; alanine aminotransferase; ambient temperature; amino acid; analysis of variance; aspartate aminotransferase; body mass; body mass index; body temperature; complete blood count; creatine kinase; ethylenediaminetetraacetic acid; fatty acid; intramuscular; monounsaturated fatty acid; nest temperature; polyunsaturated fatty acid; principal component analysis; saturated fatty acid; subcutaneous; urea/creatinine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Animals
  • Body Temperature
  • Cold Temperature
  • Fasting / physiology*
  • Fatty Acids, Unsaturated
  • Female
  • Food Deprivation
  • Male
  • Mephitidae / physiology*
  • Seasons
  • Torpor / physiology*

Substances

  • Fatty Acids, Unsaturated