Absorption of zinc deuteroporphyrin IX 2,4-bis-glycol by the neonatal rat small intestine in vivo.

Zinc deuteroporphyrin IX 2,4-bis-glycol (ZnBG) is a potent inhibitor of heme oxygenase and may be useful in the prevention of neonatal jaundice. Enteral administration could be advantageous clinically, but it has been only minimally effective with other metalloporphyrins in rats and humans. Thus, the absorption of ZnBG by the small intestine in vivo was examined. ZnBG was administered enterally at 40 mumol/kg to 2-week-old suckling rats via in situ catheterization of the small intestine. Within 15 min ZnBG was absorbed by the small intestine, as it was measured in portal and systemic venous plasma, intestine, kidney, liver, and spleen. Concentrations exceeding 5.0 microM were found in plasma within 30 min, and 9.4 microM was found in the liver after 30 min. A total of 4.6% of the administered ZnBG dose was measured in plasma and tissues.