Differences between the effect of prazosin and lysine-acetylsalicylate on some thermoregulatory parameters in nonfeverish rabbits.

Thermoregulatory responses to prazosin and lysine-acetylsalicylate (LAS) were investigated in afebrile rabbits at different ambient temperatures, i.e. at 5, 21 and 28 degrees C. In cold as well as in heat prazosin significantly inhibited the metabolic rate. This effect was accompanied by falls in rectal temperatures, particularly at the ambient temperature of 5 degrees C. Increases in ear skin temperatures became visible only when this drug was used in rabbits maintained in the thermoneutral environment. On the other hand LAS in all tested conditions indicated a marked metabolic activity associated with an intensified respiratory heat loss. As a consequence, the rabbits responded with slight increases in body temperature. The possible mode of thermoregulatory activity of prazosin is being considered in confrontation with that of LAS.