RESPONSES OF COLD- AND WARM-ADAPTED DOGS TO INFUSED NORADRENALIN AND ACUTE BODY COOLING.
Abstract
A total of 12 experiments was done in coldadapted (C-A) and warm-adapted (W-A) beagle dogs, kept more than 40 days at -10 C and 28 C, respectively. The animals, anesthetized with pentobarbital sodium were paralyzed with Flaxedil (5 mg/kg/hour) and mechanically ventilated at 28-30 C. Oxygen consumption, heart rate and colonic, pinna and paw skin temperatures were measured continuously. The dogs were infused with noradrenalin for 20 minutes at 30 C and after 45 minutes of acute cold exposure to 5 C. At 28-30 C, basal oxygen consumption was higher in C-A dogs. Oxygen consumption of C-A dogs increased with a slight increase in the heart rate during the initial 18-20 minutes after body cooling and then decreased. In W-A dogs, oxygen consumption decreased continuously after acute cold exposure. Calorigenic effects of infused noradrenalin were consistent in C-A and W-A dogs at 30 and 5 C, but there was no difference between the increased amound of oxygen consumption from the initial levels in both groups. Noradrenalin caused an increase of the heart rate in W-A dogs at 30 and 5 C, with decrease or no change in C-A dogs. Colonic, pinna and paw skin temperatures were significantly higher in C-A than in W-A dogs. Noradrenalin caused an increase in the temperatures, but the effect of the drug was more prominent in W-A than in C-A animals at lower temperature. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1965
- Accession Number
- AD0462102
Entities
People
- Loren D. Carlson
- Tetsuo Nagasaka
Organizations
- University of Kentucky