Cultured Kupffer cells/macrophages were treated with LPS (4ng/ml) in the presence of ghrelin (10−8mol/L) or control vehicle for 6 h. Cultured medium was replaced with fresh medium to withdraw LPS and ghrelin. Cells were then cultured for another 12h. Supernatants were harvested and centrifuged, then added to cultured hepatocytes pretreated with 62.5μmol/L oleic acid for 24 h. Cultured hepatocytes were stained with Oil-red O and positive signal measured by area and average diameter. n=5, * denotes P<0.05 vs control.
A. Effects of ghrelin on Kupffer cells/macrophages. Both the hepatocytes and Kupffer cells/macrophages used were isolated from wild-type mice.
B. No effects of ghrelin on Kupffer cells/macrophages isolated from GHSR1a−/− mice. Upper panel: ghrelin could not block the effect of LPS on hepatocytes isolated from GHSR1a−/− mice.
Lower panel: hepatocytes were isolated from wild-type mice, while Kupffer cells/macrophages were from GHSR1a−/− mice.