title: Low birth weight is associated with reduced nephron number and increased blood pressure in adulthood in a novel spontaneous intrauterine growth-restricted model in Yucatan miniature Swine.
abstract: BACKGROUND
  Impaired fetal growth and rapid postnatal growth are associated with programming of hypertension and metabolic syndrome in adulthood.
  
  
  OBJECTIVE
  This study evaluated this phenomenon in a novel spontaneous intrauterine growth-restricted (IUGR) model in Yucatan miniature pigs.
  
  
  METHODS
  IUGR piglets (n = 6, 3 days old, 0.73 ± 0.11 kg) were paired with a normal weight (NW) same-sex littermate (n = 6, 1.11 ± 0.13 kg), fed milk replacer for 4 weeks followed by a standard diet ad libitum for 5 h/day. At 9 months of age, arterial blood pressure (BP) telemeters were implanted to assess BP before (0.5% NaCl) and after (4.5% NaCl) a 7-day salt-loading period. At 10 months of age, nephron numbers were determined.
  
  
  RESULTS
  Prior to sexual maturity, IUGR pigs showed greater (p < 0.05) relative feed intake and experienced significant catch-up growth. Adult IUGR pigs also had higher BP (diastolic BP: 93.8 ± 5.5 vs. 90.0 ± 8.7 mm Hg, p < 0.05) and 43% fewer nephrons per kidney (p < 0.05). Nephron number was positively associated with birth weight and negatively correlated with BP (p < 0.05). Acute salt loading increased BP in both groups (p < 0.05); however, the degree of salt sensitivity was similar between groups (p > 0.05).
  
  
  CONCLUSIONS
  In conclusion, IUGR piglets have reduced nephron endowment associated with a modest BP increase in early adulthood. This new model can be used to conduct longitudinal mechanistic studies on the early programming phenomenon.
authors.affiliation: Department of Biochemistry, Memorial University of Newfoundland, St. John's, Nfld., Canada.
authors.forename: Semone B
authors.initials: SB
authors.lastname: Myrie
authors.forename: Leslie L
authors.initials: LL
authors.lastname: McKnight
authors.forename: Bruce N
authors.initials: BN
authors.lastname: Van Vliet
authors.forename: Robert F
authors.initials: RF
authors.lastname: Bertolo
mesh_terms: D000818:Animals; D001724:Birth Weight; D001794:Blood Pressure; D004195:Disease Models, Animal; D004435:Eating; D005260:Female; D005317:Fetal Growth Retardation / Q000473:pathology / Q000503:physiopathology / Q000662:veterinary*; D009399:Nephrons / Q000473:pathology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012965:Sodium Chloride; D013552:Swine; D013556:Swine, Miniature; D015430:Weight Gain
chemical_list: D012965:Sodium Chloride