ROLE OF PROSTAGLANDINS IN EXERCISE-INDUCED CORE TEMPERATURE ELEVATION IN FEMALE SPRAGUE-DAWLEY RATS

Female Sprague-Dawley rats (12:12-h photoperiod; body temperature, BT, measured with biotelemetry) with access to running wheels for 6 wk have an elevated BT (compared with rats with no access to exercise wheels, i.e, sedentary) both during the period of voluntary exercise (nighttime) (0.5-degrees-C, P = 0.0001) and the nonexercise period (daytime) (0.3-degrees-C, P = 0.002). To determine whether prostaglandin (PG) E was responsible for any portion of this daytime rise in BT, we injected a dose of sodium salicylate (300 mg/kg), which was shown to produce complete antipyresis in rats injected with lipopolysaccharide (LPS), into exercised and sedentary rats 4 h after the onset of the lights-on period. The injections of sodium salicylate led to a fall in body temperature in both the exercised and sedentary rats of similar amounts (-0.88-degrees-C vs. -0.61-degrees-C at 2 h postinjection, P = 0.59). We conclude that the increase in daytime BT of exercised female rats is not mediated by prostaglandins.