Glutamine is the major fuel for enterocytes and promotes the growth of intestinal mucosa. Although oral glutamine exerts a positive effect on intestinal villus height in very old rats, how glutamine is used by enterocytes is unclear. Adult (8 months) and very old (27 months) female rats were exposed to intermittent glutamine supplementation for 50% of their age lifetime. Treated rats received g...

The incorporation of 32Pi into phospholamban, troponin I, phosphatidylinositols, and inositol trisphosphates was studied in Langendorff-perfused guinea pig hearts stimulated with isoproterenol. Hearts were perfused with Krebs-Henseleit buffer containing [32P]Pk and freeze-clamped at different times during the positive inotropic response. Exposure of the hearts to 0.1 microM isoproterenol for up...

Phosphorylation of phospholipids was studied in Langendorff perfused guinea pig hearts subjected to beta-adrenergic stimulation. Hearts were perfused with Krebs-Henseleit buffer containing [32P]Pi and freeze-clamped in a control condition or at the peak of the inotropic response to isoprenaline. 32P incorporation into total phospholipids, individual phospholipids and polyphosphoinositides was a...

PURPOSE To investigate the effect of carbachol on the phagocytosis of photoreceptor outer segments (OS) in cultures of normal Long-Evans and dystrophic Royal College of Surgeons (RCS) rat retinal pigment epithelial (RPE) cells. METHODS Retinal pigment epithelial cells from normal and RCS rats were grown in tissue culture. On reaching confluence, they were presented with OS suspended in Krebs-...

Postischemic myocardial contractile dysfunction is in part mediated by the burst of reactive oxygen species (ROS), which occurs with the reintroduction of oxygen. We hypothesized that tissue oxygen tension modulates this ROS burst at reperfusion. After 20 min of global ischemia, isolated rat hearts were reperfused with temperature-controlled (37.4 degrees C) Krebs-Henseleit buffer saturated wit...

Purpose: To determine whether isoflurane, sevoflurane and halothane influenced hydroxyl radical production in the ischemic rat heart. Methods: Twenty-four male W~star rats were divided into four groups; control (C), isoflurane 1.496 (I), sevoflurane 2.5% (S) and halothane I% (H). The hearts were perused with modified Krebs-Henseleit bicarbonate buffer by a working heart model for I 0 min. Then,...

Preliminary evidence has suggested that hexokinase in rat heart changes its kinetic properties in response to insulin through translocation to the outer mitochondrial membrane. We reexamined this hypothesis in light of tracer kinetic evidence to the contrary. Our methods were as follows. Working rat hearts were perfused with Krebs-Henseleit buffer containing glucose (5 mmol/l) and sodium oleate...

Trimetazidine (TMZ), an anti-ischemic metabolic drug, is used to treat chest pain (angina pectoris). We hypothesized that derivatives of TMZ with antioxidant functions may improve the cardiac dysfunction caused by ischemia-reperfusion (I/R) above that observed with TMZ alone. Isolated rat hearts perfused with Krebs-Henseleit buffer according to the Langendorff method were subjected to 30 min of...

OBJECTIVE Due to limited resources, improvement of preservation solutions is still of great importance in cardiac transplant surgery. New additives with antioxidant properties were tested with respect to coronary function of isolated rat hearts. METHODS Bretschneider HTK solution containing none or an antioxidant additive (deferoxamine, trolox or LK 616) was used for 8h cold cardioplegia. Aft...

The cardioprotective effect of calmodulin antagonists, trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7) was examined on the isolated rat heart exposed to hypothermic and ischemic conditions by measuring distribution of lysosomal enzymes in myocardial cells, and leakage of creatine kinase (CK) during reperfusion and postischemic recovery in myocardial systolic ...