Effect of enteral versus parenteral nutrition on LPS-induced sepsis in a rat model

The purpose of the present study was to determine whether total enteral nutrition (TEN) or total parenteral nutrition (TPN) differ in their modulation of ghrelin production and cardiac dysfunction induced by lipopolysaccharide (LPS).

Vascular catheters or gastrostomy tubes were surgically placed into rats who received isocaloric parenteral or enteral nutrition postoperatively. After 7 d, the rats were injected intravenously with LPS (2.5 mg/kg). Serum ghrelin levels were determined by enzyme-linked immunosorbent assay and myocardiac function was assessed via the Langendorff isolated heart technique.

Before and after the administration of LPS, TEN was found to be more effective at increasing the plasma ghrelin levels than TPN. After LPS administration, left-ventricular developed pressure decreased in animals receiving TPN when compared with animals receiving TEN. Animals receiving TPN also had significant reductions in their maximal rates of increase (+dp/dt max) and decrease (-dp/dt max) in left ventricular pressure when compared with animals receiving TEN (unpaired t-test, P < 0.05). Upon reperfusion after 30 min of ischemia, the left ventricular resting tension decreased in animals receiving TPN compared with animals receiving TEN. Thereafter, left-ventricular developed pressure, +dp/dt max, and -dp/dt max decreased in the TEN recipients in comparison to the TPN-receiving animals.

We conclude that TEN more effectively increases plasma ghrelin levels than TPN. The maintenance of higher ghrelin levels in TEN-fed rats is associated with maintaining cardiac function during LPS-induced septic shock.