The Effect of Hydrocortisone, Thyroxine, and Phenobarbital on Diamine Oxidase Activity in Newborn Rat Intestine

Abstract

ABSTRACT. There is a reported association between administration of prenatal glucocorticoids and a decreased incidence of necrotizing enterocolitis in human infants. In rats, the degree of ischemic bowel disease correlates negatively with intestinal diamine oxidase (E.C. 1.4.3.6) activity. Since the administration of hydrocortisone, thyroxine, or phenobarbital to newborn rat pups affects the development of intestinal enzymes, we were interested in knowing whether hydrocortisone, thyroxine, or phenobarbital specifically affect intestinal diamine oxidase activity. We injected rat pups with hydrocortisone sodium succinate, 1-thyroxine pentahydrate, sodium salt, sodium phenobarbital, or the control solution on days 4, 6, 8, or 10 of life (phenobarbital, days 3, 5, 7, or 9). Pups were injected 3 days consecutively (phenobarbital, 4 days), and all were sacrificed on days 7, 9, 11, and 13. Intestinal diamine oxidase and intestinal invertase (E.C. 3.2.1.26) activities were measured. Invertase was used as a control enzyme because it is known to be induced by glucocorticoid hormones. We found that the hydrocortisone-injected pups lvad 10-fold higher specific activity of invertase than the saline-injected animals. Diamine oxidase activity was significantly higher in the group receiving hydrocortisone and sacrificed on days 7,9, and 11. Enzyme activity in both the hydrocortisone-injected and saline-injected groups was equal on day 13, as was enzyme activity on all days in the thyroxine-injected and sodium hydroxide-injected groups, and the phenobarbital-injected and the saline-injected groups. Our results suggest that diamine oxidase activity may be induced by hydrocortisone, but is not affected by thyroxine or phenobarbital. (Pediatr Res 21: 368-370, 1987)

Models of the pathogenesis of necrotizing enterocolitis

“…9 This immaturity may relate to mucosal integrity or permeability, 1~ and also to the regulation of gastrointestinal blood flow, 1~ motility, 12 or enzyme function. 13 Additional observations have emphasized the role of various perinatal risk factors. Because many of these factors produce hypoxia and ischemia of the gastrointestinal tract, vascular compromise has been proposed as a theoretic event NEC Necrotizing enterocolitis PAF Platelet activating factor TNF Tumor necrosis factor in the pathogenesis.…”