The circannual variations of total serum lipids and cholesterol with respect to body weight in the woodchuck (Marmota monax) [Les variations des lipides sériques totaux et du cholesterol en relation avec la masse corporelle chez la marmotte (Marmota monax)].

Résumé

Woodchucks spend the active summer months building fat depots for survival through the cold winter months of hibernation. Their seasonal body weight reflected these changes with an increase during the summer and early fall and a decrease during the winter months. 2- The total serum lipid levels gradually increased during the summer and early fall. When animals were placed into a hibernaculum at 6 C there was a dramatic decrease in total serum lipids which may suggest the presence of a cold sensitive enzyme in lipid synthesis of this animal. 3- The synthesis of cholesterol was not cold sensitive, however, and the total serum levels continued to rise for 2 months after the animals were placed into the hibernaculum. After December the level slowly dropped to the summer values.