title: Recovery from ischemic acute renal failure is improved with enteral compared with parenteral nutrition.
abstract: OBJECTIVE
  To compare measurements of renal function after acute ischemic renal failure in rats fed enterally or parenterally.
  
  
  METHODS
  Prospective, randomized, animal trial.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Male Sprague-Dawley rats (n = 21).
  
  
  METHODS
  Animals were randomized to receive isocaloric (160 nonprotein kcal/kg/day), or isonitrogenous (1.4 g of nitrogen/kg/day [100 mmol/kg/day]) enteral (n = 10), or parenteral nutrition (n = 11) through either a gastrostomy tube or a catheter placed in the jugular vein. After the animals received 7 days of assigned feedings, baseline blood samples were collected. A right nephrectomy and 45-min left renal pedicle occlusion were then performed. One hour after the ischemic injury, assigned feedings were resumed and continued for 3 days. After ischemic injury, daily blood samples were obtained and 24-hr urine collections were performed. On day 11, animals were killed and the kidney was harvested and fixed for subsequent microscopic examination.
  
  
  RESULTS
  Urine was analyzed for concentrations of total urea nitrogen, creatinine, protein, and calcium. Serum was analyzed for creatinine and urea nitrogen concentrations. Fixed kidney sections were examined for mitotic figures, tubular calcifications, and casts using light microscopy by an investigator blinded to the nutritional regimen. Data are presented as mean +/- SD or median (range). Percent increase in creatinine clearance from the nadir on day 9 to day 11 was approximately 2.5-fold greater in the enteral compared with the parenteral nutrition group (490 +/- 221% vs. 208 +/- 130%; p = .003). Histologic evaluation demonstrated greater dystrophic tubular calcifications per ten high-power fields in the parenteral compared with the enteral nutrition group (50 [four to 85] vs. three [0 to 37]; p = .001). No differences in urine calcium concentration or 24-hr calcium excretion were seen.
  
  
  CONCLUSIONS
  Rats given continuous enteral nutrition 7 days before and for 3 days after ischemic acute renal failure have improved renal function compared with rats given parenteral nutrition.
authors.affiliation: School of Pharmacy, University of Connecticut, Storrs 06269-2092, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Mouser
authors.forename: E B
authors.initials: EB
authors.lastname: Hak
authors.forename: D A
authors.initials: DA
authors.lastname: Kuhl
authors.forename: R N
authors.initials: RN
authors.lastname: Dickerson
authors.forename: L W
authors.initials: LW
authors.lastname: Gaber
authors.forename: L J
authors.initials: LJ
authors.lastname: Hak
mesh_terms: D058186:Acute Kidney Injury / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D000818:Animals; D004750:Enteral Nutrition; D007511:Ischemia / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D007668:Kidney / Q000098:blood supply* / Q000503:physiopathology; D008297:Male; D010288:Parenteral Nutrition; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors