title: Amniotic fluid stem cells prevent development of ascites in a neonatal rat model of necrotizing enterocolitis.
abstract: OBJECTIVE
  It has been demonstrated that in a neonatal rat model of necrotizing enterocolitis (NEC), amniotic fluid stem (AFS) cells decrease intestinal damage and improve survival via modulation of stromal cells expressing cyclooxygenase 2 in the lamina propria. Herein, we aimed to evaluate the effect of AFS cells on body weight and fluid retention in this NEC model. Methods AFS cells were obtained from green fluorescent protein (GFP) + pregnant rats at E16 and expanded in culture. A total of 185 neonatal rats had NEC induced by gavage feeding of hypertonic formula + hypoxia + oral lipopolysaccharide (4 mg/kg/d) and were randomized to intraperitoneal phosphate buffered saline (PBS, n = 93) or AFS cells (n = 92). A total of 36 breastfed (BF) rats were used as controls. All rats were being killed at 96 hours of life. Groups were compared for body weight and presence of free intraperitoneal fluid using nonparametric and contingency tests. Data are expressed as mean ± standard deviation.
  
  
  RESULTS
  There were no differences in birth weight among the groups (PBS = 5.6 ± 0. 3 g; AFS cells = 5.6 ± 0. 3 g; BF = 5.6 ± 0. 3 g; p = 1). The body weight at randomization was not different between PBS (5.61 ± 0. 5 g) and AFS cells (5.60 ± 0. 5; p = 1) rats. After the rats were killed, BF rats were significantly heavier (12.5 ± 0.1 g) than PBS (5.12 ± 0.4 g) and AFS cell rats (4.95 ± 0.3; p < 0.0001). From randomization to being killed, PBS rats had 9% of weight loss in comparison with 12% in AFS cell rats (p = 0.08). After the rats were killed, 42 (45%) PBS rats developed ascites with evident abdominal distension in comparison with 19 (21%) AFS cells (p = 0.0005). None of BF animals had ascites.
  
  
  CONCLUSIONS
  Gavage feeding and undernutrition severely affect growth in this model of NEC. Administration of AFS cells result in lower incidence of ascites than in PBS rats. This could explain the differences in body weight between the two groups of rats that were killed. Furthermore, studies on liver function and fluid composition are needed to investigate our speculation.
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Augusto
authors.initials: A
authors.lastname: Zani
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Mara
authors.initials: M
authors.lastname: Cananzi
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lauriti
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Francesco
authors.initials: F
authors.lastname: Fascetti-Leon
authors.affiliation: Centre for Advanced Biomedical Imaging, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Jack
authors.initials: J
authors.lastname: Wells
authors.affiliation: Centre for Advanced Biomedical Imaging, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Bernard
authors.initials: B
authors.lastname: Siow
authors.affiliation: Centre for Advanced Biomedical Imaging, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Lythgoe
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Agostino
authors.initials: A
authors.lastname: Pierro
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Eaton
authors.affiliation: Department of Pediatric Surgery, University College London Institute of Child Health, London, United Kingdom.
authors.forename: Paolo
authors.initials: P
authors.lastname: De Coppi
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology*; D000818:Animals; D000831:Animals, Newborn; D001201:Ascites / Q000473:pathology / Q000517:prevention & control*; D001835:Body Weight; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004195:Disease Models, Animal; D020345:Enterocolitis, Necrotizing / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D007274:Injections, Intraperitoneal; D007422:Intestines / Q000473:pathology; D008279:Magnetic Resonance Imaging; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D033581:Stem Cell Transplantation
chemical_list: D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat