Effect of intravenous feeding on wound healing in starvation: an experimental study on the rabbit

The effects of modified protein sparing therapy (PSP) and total parenteral nutrition (TPN) on total and wound metabolism were studied for 96 hours after laparotomy and a small gastric excision in 40 rabbits starved for seven days. A further eight starved and eight non-starved animals served as controls for the blood variables. Normal healing up to day 14 was studied in 20 non-starved animals. The difference in deaths and animals in poor condition, 42.1 per cent in PSP and 18.6 per cent in TPN, respectively, was clear but statistically non-significant. PSP led to a lower mean serum albumin concentration than TPN, 25.7 +/- 3.7 (SD) and 28.7 +/- 3.0 (p = 0.02), respectively. The animals receiving PSP excreted significantly more 3-methylhistidine. TPN maintained a positive nitrogen balance, but PSP produced a negative one. The collagen content of the skin scar was lower after PSP (3.1 +/- 0.7 mg) than after TPN (4.5 +/- 1.3 mg) (p less than 0.05), the latter coming close to the level for normal 4-day healing, 4.5 +/- 1.2 mg. Prolyl 4-hydroxylase (PPH) activity showed no difference. No inter-group differences in collagen were found in the stomach. Both regimens totally reversed the starvation-induced decrease in PPH activity in the stomach, but only partially in skin. Thus TPN produced better total and skin wound metabolism after laparotomy and starvation than did PSP. No differences in visceral wound healing were observed.