Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/19/1998
Publication Date: N/A
Technical Abstract: Our objective was to investigate endotoxin-induced hypothermia in neonatal pigs. In Part I, the effect of environmental temperature (ET) on endotoxin response was investigated in 36 male piglets. At 24 hr of age, piglets were placed in environmentally controlled chambers maintained at 18 deg C or 34 deg C (n=18/ET). Rectal temperatures (RT) were obtained prior to an i.p. injection of saline (Cont; n=9/ET) or lipopolysaccharide (LPS; 150 ug/kg; n=9/ET) and every 15-min for 3 hr. There was a TIME X ET X LPS interaction (P<0.0001) such that pigs at 18 deg C reacted more adversely to LPS than those at 34 deg C. At 18 deg C, RT for LPS pigs was lower (P=0.004) than that of Cont. At 34 deg C, there was no effect of LPS on RT (P>0.88). Serum cortisol (CS) was elevated in all LPS pigs regardless of ET (P<0.04), however the response was greater for LPS pigs at 18 deg C (196.8 ng/ml) vs 34 deg C (93.8 ng/ml). In Part II, we investigated the ability of indomethacin (IND), an inhibitor of prostaglandin production, t prevent the hypothermic effect of LPS at 18 deg C. Forty male pigs (24 hr old) were divided into 2 pre-treatment (PRE) groups: 1)Control (saline) and 2) IND (10 mg/kg). One hr following PRE, pigs received a second i.p. injection of either saline or LPS (150 ug/kg). RT was monitored every 15 min beginning with the PRE period and for 3 hr afterwards (POST). There was no effect of IND on RT during the PRE period. In the POST period, there was a TIME X IND X LPS interaction (P<0.0001) such that IND during PRE prevented the LPS-induced reduction in RT. Interestingly, IND during the PRE did not prevent the LPS-induced increase in CS (IND X LPS; P>0.23). These results provide evidence that both ET and IND can be utilized effectively to prevent LPS induced hypothermia in neonatal pigs.