Effects of fish oil-based lipid emulsion on inflammation and kidney injury in mice subjected to unilateral hind limb ischemia/reperfusion

This study investigated the effects of a fish oil-based lipid emulsion (FO) on local skeletal muscle and remote renal damage at 72 h post-reperfusion in a murine model of hind limb ischemia-reperfusion (IR) injury. Mice were assigned to 1 sham group and 3 IR groups. The IR groups were treated daily with either saline or FO from 3 days prior to limb ischemia till 3 days after reperfusion. Limb IR was induced by applying a 4.5-oz orthodontic rubber band above the left greater trochanter for 120 min followed by band-released reperfusion for 72 h. Mice were then sacrificed to harvest blood, muscle, and kidney for analysis. The results showed that IR injury led to upregulation of pro-inflammatory monocytes in blood, infiltration of leukocytes into injured muscle, and over-expression of pro-inflammatory genes in muscle and kidney tissues. Supplementing FO either before or after IR injury alleviated IR-induced inflammatory gene expressions in muscle and kidney tissues. Furthermore, FO given after IR injury reduced circulating pro-inflammatory monocytes, limited muscle leukocytic infiltration, and improved renal histology. These results suggest that FO may protect the muscles from IR injury. FO given after IR injury can better downregulate the inflammation seen in IR-induced remote kidney injury.