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Intestinal ischemia in the newborn: the role of intestinal maturation
C A Musemeche1, R P Pizzini, R J Andrassy
1Department of Surgery, University of Texas Medical School, Houston 77030.
Insights
Hydrocortisone treatment reduced xanthine oxidase and increased maltase in neonatal rats, mitigating platelet-activating factor-induced intestinal ischemia. This suggests hydrocortisone may protect immature intestines from ischemic injury.
Area of Science:
- Neonatal physiology
- Gastrointestinal pathophysiology
- Pharmacology
Background:
- Premature infants' immature intestinal tracts increase susceptibility to intestinal ischemia.
- Exogenous glucocorticoids are known to accelerate intestinal maturation.
Purpose of the Study:
- To investigate the protective effects of hydrocortisone on platelet-activating factor (PAF)-induced intestinal ischemia in neonatal rats.
Main Methods:
- Neonatal Sprague-Dawley rats received intraperitoneal injections of saline or hydrocortisone.
- Intestinal ischemia was induced using platelet-activating factor (PAF) or saline.
- Intestinal tissue was analyzed for enzyme activity (maltase, lactase, myeloperoxidase, xanthine oxidase) and histology.
Main Results:
- Hydrocortisone significantly decreased xanthine oxidase (XO) levels in both saline and PAF-treated groups compared to controls.
- Maltase levels were significantly elevated in hydrocortisone-treated groups, particularly in the PAF-induced ischemia group.
- Histological examination revealed that 7 out of 8 rats in the saline + PAF group developed ischemia, while hydrocortisone treatment appeared to mitigate this effect.
Conclusions:
- Hydrocortisone administration significantly reduced XO and increased maltase activity in neonatal rats.
- These findings suggest hydrocortisone may offer protection against PAF-induced intestinal ischemia in immature intestines.
Abstract:
Premature infants are susceptible to intestinal ischemia during the newborn period when their intestinal tracts are functionally and structurally immature. Studies have shown that exogenous glucocorticoids hasten intestinal maturation. We investigated the effects of hydrocortisone on platelet activating factor (PAF)-induced intestinal ischemia in the neonatal rat. On Postnatal Days 7-11, Sprague-Dawley rats were given intraperitoneal (ip) injections of either saline (SAL) or hydrocortisone (HC; 50 mg/kg total). On Day 12, rats were injected with either PAF (2 micrograms/kg) or an equal volume of saline. After 2 hr the rats were sacrificed and sections were taken for histology. The remaining intestine was analyzed for maltase, lactase, myeloperoxidase (MPO), and xanthine oxidase (XO). Experimental groups were as follows: SAL (N = 8), received saline only; SAL+PAF (N = 8), received saline plus PAF; HC (N = 3), received hydrocortisone+saline; and HC+PAF (N = 5), received hydrocortisone plus PAF. XO was significantly decreased (P < 0.001) in the hydrocortisone-treated groups (HC + SAL = 16.36 +/- 18.42 units/g protein, HC + PAF = 17.33 +/- 9.06 units/g protein) vs the controls (SAL only = 108.90 +/- 20.24 units g/protein, SAL + PAF = 145.77 21.28 units/g protein). MPO was not significantly elevated in SAL + PAF (4.60 +/- 0.95 units/g protein) vs HC + PAF (2.18 +/- 0.80 units/g protein) in this study. Maltase was significantly elevated (P < 0.001) in the HC + PAF (241.46 +/- 40.6 mole/min/g protein) and HC + SAL (152.78 +/- 16.35 mole/min/g protein) vs saline only (28.35 +/- 5.77 mole/min/g protein and SAL + PAF (37.29 +/- 8.70 mole/min/g protein. Animals (7/8) in the SAL + PAF group developed ischemia by inspection and histologic exam.(ABSTRACT TRUNCATED AT 250 WORDS)