Regional heterothermy and cardiovascular responses during induced hypothermia in non-hibernated and hibernated woodchucks, Marmota monax [Hétérothermie régionale et réponses cardiovasculaires au cours d’une hypothermie induite chez des marmottes américaines hibernantes et non hibernantes].

Résumé

L'hypothermie provoquée entraîne une diminution plus prononcée de la pression sanguine, de la température carotidienne au moment de l'arrêt cardiaque, une hétérothermie régionale et une résistance au froid plus prononcée chez les animaux au sortir de l'hibernation. 1. Immediately prior hibernation enhanced the physiological performance of woodchucks Marmota monax, during induced hypothermia as compared to non-hibernated woodchucks (NH). 2. Carotid systolic blood pressure was lower in hibernated woodchucks (H) than in NH down to a carotid temperature of 13° C. 3. Carotid temperature at cardiac arrest was lower in H (3,4 °C) than in NH (7,3 °C). 4. Regional heterothermy was more pronounced in H with the maximal differential between carotid and colon being 7,8 °C in H and 1,5 °C in NH. 5. Resistance to cooling was greater in H with a cooling rate (min/kg per C) of 10,5 for H and 4,3 for NH over a carotid temperature range of 30-10 °C.