Both growth hormone and exogenous glutamine increase gastrointestinal glutamine uptake in trauma

The authors studied the effect of exogenous glutamine (GLN), with and without growth hormone (GH), pretreatment, on gastrointestinal, hepatic, femoral, and renal GLN fluxes.

Growth hormone treatment increases gastrointestinal uptake of GLN despite a reduced skeletal muscle and whole body release.

Piglets were randomized to a GH + GLN group (n = 8), a GLN group (n = 8), a GH group (n = 8), and a control group (CON; n = 8). Genotropin (Pharmacia, Stockholm, Sweden; 24 international units; correspondingly saline in the GLN and the CON group) was given daily 3 days before and at the onset of trauma (surgery). Organ fluxes and whole body release of GLN were determined 1 and 5 hours after surgery. An infusion of GLN 36 micrograms/kg per minute was started after the first measurement in the GH + GLN and the GLN groups.

Both GH treatment and exogenous GLN increased gastrointestinal GLN uptake (p = 0.001 and p = 0.02, respectively). Growth hormone treatment reduced hepatic GLN uptake (p = 0.001). Hepatic GLN uptake was lower in the GH + GLN group versus the GH group (p = 0.02), but not in the GLN group versus the CON group (p = 0.98). Growth hormone treatment reduced femoral and whole-body GLN release (p = 0.0001 and p = 0.02, respectively). Renal GLN uptake was higher in the two GH-treated groups (p = 0.003).

Both exogenous GLN and GH increased gastrointestinal GLN uptake, and the combination was additive. In contrast to exogenous GLN, GH reduced hepatic uptake and consequently facilitated the increased gastrointestinal GLN uptake that occurred despite reduced femoral and whole-body release.