Inflammatory enzyme composition of the neonatal rat intestine: implications for susceptibility to ischemia.
Recent evidence has suggested that the immaturity of the neonatal intestine may play a key role in the development of ischemic injury. However, relatively little data exist on the susceptibility of the neonatal intestine to ischemic injury at various ages especially in the fed versus fasted states. In this study, the levels of xanthine oxidase ([XO] an enzyme which is a known, major source of free radicals in postischemic tissue) and myeloperoxidase ([MPO] an index of tissue neutrophil infiltration) were measured in 1-, 5-, 10-, 15-, and 20-day-old Sprague-Dawley rats. Rats were divided into fed (n = 8/day) and fasted (n = 8/day) groups 4 hours prior to sacrifice. The entire small intestine was removed and divided into five segments: the duodenum, proximal jejunum, distal jejunum, proximal ileum, and distal ileum. The specimens were homogenized and assayed for XO and MPO levels. A significant increase in XO was observed in the fasted animals compared to the fed animals on all days. Peak levels in XO were observed in both groups from day 5 to 10. MPO levels were significantly higher in the fasted versus fed animals on day 1. MPO levels decreased as the animals aged. These data demonstrate dramatic differences in the levels of inflammatory enzymes of the newborn rat in the fed versus fasted states. Also, marked variations with age are seen in both XO and MPO. Whether the XO and MPO levels present at the time of ischemic insult affect severity of injury remains to be seen.
Musemeche
C A
CA
Department of Surgery, University of Texas Medical School, Baylor College of Medicine, Houston.
Henning
S J
SJ
Baker
J L
JL
Pizzini
R P
RP
D000818:Animals; D000831:Animals, Newborn; D004761:Enterocolitis, Pseudomembranous / Q000201:enzymology / Q000503:physiopathology; D005215:Fasting; D007421:Intestine, Small / Q000098:blood supply* / Q000201:enzymology*; D007511:Ischemia / Q000201:enzymology*; D009195:Peroxidase / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014969:Xanthine Oxidase / Q000032:analysis*
D009195:Peroxidase; D014969:Xanthine Oxidase