Gut permeability in paediatric cardiac surgery.

Background: Intestinal mucosal ischaemia can occur in infants and children during and after cardiac surgery. Severe decreases in mucosal perfusion may cause complications such as necrotizing enterocolitis and postoperative mortality. We investigated gut permeability in paediatric patients undergoing cardiac surgery using the dual sugar permeability test and absorption of two other saccharides.

Not prostacyclin synthase but prostaglandin endoperoxide synthase increases with human placental development.

Prostaglandin endoperoxide synthase (i.e. cyclooxygenase; PGH synthase) and prostacyclin synthase (PGI synthase) were quantitated with specific immunoradiometric assays in microsomes from human placentae (n = 20) obtained from 7 up to 17 weeks of gestation.

Distribution of prostaglandin endoperoxide synthase and prostacyclin synthase in the late pregnant uterus.

Prostacyclin (PGI2) synthase and prostaglandin endoperoxide synthase (cyclo-oxygenase; PGH synthase) were measured with specific immunoradiometric assays in myometrial microsomes from different areas of a primigravid uterus at 34 weeks gestation. PGH synthase concentrations increased significantly from fundus toward lower segment (P less than 0.005), but that trend did not apply to PGI2 synthase concentrations, which were significantly higher on the placental than on the non-placental side of the uterus (P less than 0.

Does or can human placenta produce prostacyclin?

In order to resolve contradictory data on the capacity of the human placenta to produce prostacyclin (PGI2), we have quantified PGI2 synthase in 12 placentae obtained in the first trimester of pregnancy. Using a specific immunoradiometric assay and two monoclonal antibodies against the enzyme, we found PGI2 synthase to be present in the microsomal fraction of all placentae investigated, albeit in concentrations that were 1000-fold lower than in bovine aortal microsomes and 100-fold lower than in both pregnant and non-pregnant myometrium. Comparison of these data with previous reports on placental PGI2 production suggests that the contradictions between previous data are more apparent than real.

Increase in placental 15-hydroxy-prostaglandin dehydrogenase in the first half of human pregnancy.

NAD-dependent 15-hydroxy-prostaglandin dehydrogenase (PGDH) activity was measured in homogenates of 25 human placentae obtained between 7 and 17 weeks of gestation. PGDH activity, expressed in nanomoles PGF2 alpha metabolized per min, ranged from 0.2 to 5.