Abstract
The thermosensitivity of the preoptic area/anterior hypothalamus (POA/AH) was determined in conscious rabbits by measuring metabolic rate at various POA/AH temperatures between 33 and 42°C and calculating the slope (b) of the regression of metabolic rate on POA/AH temperature. The value of b ranged from -0.118 W/kg-1/°C-1 to -1/46 W/kg-1 in different rabbits, but was reproducible in any one animal. An important factor contributing to the between animal differences appeared to be the location of the thermode thermocouple array. Injection of bacterial pyrogen into the lateral cerebral ventricle decreased the value of b in all cases. The range after pyrogen injection was -0.037 to -0.613 W/kg-1/°C-1. On the average, pyrogen depressed POA/AH thermosensitivity by 40% (31-47%, in different animals). In one animal, intravenous pyrogen also depressed POA/AH thermosensitivity. These data indicate that the shift in thermoregulation leading to fever is produced or accompanied by a depression of central thermosensitivity.
Original language | English |
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Pages (from-to) | 1067-1073 |
Number of pages | 7 |
Journal | American Journal of Physiology |
Volume | 227 |
Issue number | 5 |
DOIs | |
State | Published - 1974 |
Externally published | Yes |