The control of shivering and non-shivering thermogenesis in the rat.
1. The effect of intraperitoneal administration of propranolol (4, 8 and 12 mg/kg) on colonic temperature was studied in twelve rats during exposure to ambient temperatures of 30, 15 and 5 degrees C. 2. At 30 degrees C, propranolol had no effect on colonic temperature; at 15 and 5 degrees C, however, 4 mg propanolol/kg induced a fall in colonic temperature of about 0-8 degrees C, whereas 8 and 12 mg propanolol/kg induced a fall of about 1-5-2-0 degrees C. 3. Assuming that the temperature regulations system of the rat has a proportional controller and that the effect of propranolol was due to the blockade of non-shivering thermogenesis, the results are interpreted as showing that shivering is activated only when heat loss exceeds the capacity for non-shivering thermogenesis.
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D001833:Body Temperature Regulation; D003106:Colon / Q000187:drug effects; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D012768:Shivering; D013696:Temperature
D011433:Propranolol