T. Manner

The use of an intravenous fish oil emulsion enriched with omega-3 fatty acids in patients with cystic fibrosis

The effects of parenteral nutrition supplemented with a lipid emulsion enriched with the omega-3 fatty acids (FA), eicosapentaenoate (20:5n-3) and docosahexaenoate (22:6n-3), derived from fish oil were compared to a standard lipid emulsion containing omega-6 FA in patients with cystic fibrosis (CF). Patients were randomized to receive either Omegavenous 10%, which contains fish oil (IFO), or Liposyn III 10% (control) daily for 1 mo at a dose of 150 mg/kg. There were no observed allergic or toxic reactions, no abnormalities in liver function tests or coagulation parameters. To assess the bioavailability of the lipid administered, measurement of plasma free fatty acid (FFA) levels were made of the essential FA. There were no adverse changes in plasma levels of the omega-6 FA (18:2n-6, 18:3n-6, 20:3n-6, and 20:4n-6), and plasma levels of the omega-3 FA (20:5n-3 and 22:6n-3) increased significantly during the 1-mo study. There were no significant changes in plasma FFA profiles of the essential FA for the patients receiving the control lipid. The effect of treatment on pulmonary function was also investigated. There were no significant changes in FVC, FEV1, PEFR, FEV1/ FVC, or FEF25-75 (absolute value or percentage) over the 4 weeks of study in the group receiving IFO or control. This preliminary investigation suggests that intravenous administration of fish oils enriched with long chain omega-3 FA to patients with CF is safe and bioavailable.

Effect of substrate manipulation on reducing ischemia/reperfusion injury in isolated perfused rat hearts.

The objective of this investigation was to assess the effect of substrate manipulation on reducing ischemia/reperfusion injury (IRI). Isolated rat hearts were perfused with modified Krebs-Henseleit buffer containing either (in mM): glucose 11 (G1), glucose 22 (G2), or glucose 11 with either xylitol 11 (GX), mannitol 11 (GM), L-leucine 1 (GL), or L-glutamic acid 2 (GGA), respectively. Hearts were subjected to 10 min of global no-flow ischemia, followed by 20 min of reperfusion. Mean tissue perfusion, oxygen consumption, and peak left ventricular pressure (PLVP) were determined at baseline, in the first minute of regular heart rhythm following ischemia, and after 20 minutes of reperfusion. Reperfusion arrhythmia (in sec) was significantly (all p < 0.05) shorter in GGA (115 +/- 33) vs G1 (315 +/- 29) and G2 (273 +/- 33), and also in GL (161 +/- 26) vs G1. Dry/wet heart weight ratios were also greater in GGA (0.20), when compared with G2 (0.16), GX (0.17), GM (0.17), GM (0.17), and GL (0.17) (all p < 0.02), suggesting less cellular/interstitial edema. Percent recovery in PLVP was improved (p < 0.03) in GL (81 +/- 2) and GGA (81 +/- 2) vs. G2 (71 +/- 3), without significant alterations in oxygen consumption. Thus, cardiac IRI can be diminished by substrate manipulation, especially by augmentation of glutamate and leucine, most likely due to an improved anaerobic energy generation and utilization.