Bacterial lipopolysaccharide shifts fasted plasma ghrelin to postprandial levels in rats

Lipopolysaccharide (LPS) injected intraperitoneally (i.p.) is known to decrease food intake. Ghrelin is a peptide hormone produced by the stomach with a potent orexigenic effect and plasma levels that are inversely correlated with the fed state. We examined changes in plasma ghrelin levels 3 h after LPS (100 mug/kg, i.p.) in fasted rats with or without a 1 h re-feeding period. LPS injection decreased the fasting levels of ghrelin by 51 +/- 5% compared with preinjection values while i.p. vehicle did not modify ghrelin levels in fasted rats. LPS at this dose reduced fasting-induced food intake by 60% compared with the i.p. vehicle group. Re-feeding decreased plasma ghrelin levels by 58 +/- 3% compared with pre-feeding fasting values in i.p. vehicle group. These data provide the first evidence that LPS shifts fasting ghrelin levels to those observed postprandially. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.