title: Pancreatic development in newborn guinea pigs fed intact or low-hydrolyzed protein formulas.
abstract: OBJECTIVE
  To evaluate pancreatic development in newborn guinea pigs fed since birth intact or low-hydrolyzed protein formulas compared with breast milk.
  
  
  METHODS
  Forty-five newborn guinea pigs were allocated to three feeding regimens: breast milk (n=15) and two isocaloric isonitrogen milk formulas containing intact (n=15) or low-hydrolyzed proteins (n=15). Body weight and food consumption were recorded every day. After 8 days, one third of pups from each group was killed, and the remaining animals were weaned. Another third was killed on day 14, and the remainders were killed on day 20. Zymogen storage was evaluated on pancreatic sections, whereas DNA and RNA concentrations were measured by a fluorometric method.
  
  
  RESULTS
  Compared with breast fed pups, both groups of artificially fed animals showed lower weight gain during the first 2 weeks of life but not after weaning. Both formulas fed groups had significantly lower amount of zymogen granules in pancreatic acinar cells at 8 and 14 days of life. This reduction was still present at day 20 in intact protein formula but not in low-hydrolyzed protein formula fed animals in which higher RNA/DNA ratio was also observed compared with breast fed pups.
  
  
  CONCLUSIONS
  In newborn guinea pigs, artificial feeding is associated with reduced zymogen storage at days 8 and 14 of life. After weaning, cellular content of zymogen granules is comparable with breast fed pups only in low-hydrolyzed protein formula fed animals, even in the presence of some evidence of pancreatic hypoplasia.
authors.affiliation: Institute of Pediatrics and Neonatology, University of Milan, Milan, Italy. carla.colombo@unimi.it
authors.forename: Carla
authors.initials: C
authors.lastname: Colombo
authors.forename: Arianna
authors.initials: A
authors.lastname: Biffi
authors.forename: Massimo
authors.initials: M
authors.lastname: Agosti
authors.forename: Andrea
authors.initials: A
authors.lastname: Crosignani
authors.forename: Veronica
authors.initials: V
authors.lastname: Bennato
authors.forename: Antonio
authors.initials: A
authors.lastname: Marini
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000187:drug effects*; D004044:Dietary Proteins / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004435:Eating / Q000187:drug effects; D005526:Food, Formulated; D006168:Guinea Pigs; D006801:Humans; D006868:Hydrolysis; D007231:Infant, Newborn; D010179:Pancreas / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011897:Random Allocation; D022142:Secretory Vesicles / Q000187:drug effects*; D013997:Time Factors; D014886:Weaning
chemical_list: D004044:Dietary Proteins