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Pharmacological preconditioning, including that with geranylgeranylacetone (GGA) and volatile anesthetics, has been shown to confer cardiac protection from ischemia/reperfusion injury although the mechanisms for this protection are poorly understood. Caveolins, integral membrane proteins that act as scaffolding proteins in caveolar membranes, localize molecules involved in cardiac protection. We have tested the hypothesis that caveolin-3 (Cav-3), the predominant isoform in cardiac myocytes, is essential for the synergistic effect observed between GGA and volatile anesthetics.Mice were randomly assigned to receive GGA, isoflurane [0.5 and 1.0 minimum alveolar concentration (MAC)], or GGA + isoflurane (0.5 MAC). An in vivo mouse model of ischemia/reperfusion injury was tested in wild-type and Cav-3 knockout mice, and the infarct size was determined. Biochemical assays were also performed in excised hearts.Geranylgeranylacetone and therapeutic isoflurane (1.0 MAC) independently reduced infarct size (31.6 ± 6.1 and 28.0 ± 5.0% of the area at risk, respectively; n = 10) as compared to the controls (45.8 ± 9.4%; n = 10). The combination GGA + sub-therapeutic isoflurane (0.5 MAC) further decreased the infarct size to 19.3 ± 5.1% (n = 10). Preconditioning [GGA, isoflurane (1.0 MAC), and GGA + isoflurane] increased the amount of Cav-3 protein in the discontinuous sucrose-gradient buoyant fractions. Additionally, cardiac protection was not observed in Cav-3 knockout mice following the administration of GGA, isoflurane, and GGA + isoflurane.Combined administration of GGA + isoflurane had a synergistic effect, enhancing the protection against myocardial infarction to a greater extent than either drug alone. This beneficial effect is mediated by Cav-3 expression.

BACKGROUND: Anti-cancer pharmaceuticals frequently have adverse side effects on patients such as gastrointestinal involvement limiting their clinical applications. These effects may be controlled by nutritional interventions, however, there are few studies that have shown any mechanistic effects. In this study, we examined effects of diet enhanced with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on 5-fluorouracil (5-FU)-induced intestinal impairment and immunity in mice. METHODS: C57Bl6 mice were randomized to control diet, control diet + EPA, control + DHA, control + fish oil, or diet enchanced with DHA/EPA. After seven days of each respective diet, mice, excluding those in the sham group, were treated with 10 mg/kg/day 5-FU for 7 days. The effects of 5-FU-induced impairment in the small intestine were assessed using cytokine concentrations in serum and tissue, secretory immunoglobulin (Ig) A, diamine oxidase (DAO) activity, the length of the small intestine, and the expression of apoptosis signaling genes. RESULTS: The EPA/DHA-enhanced diet resulted in the most beneficial, synergystic and protective effect against 5-FU induced weight loss. Protection against inflammation, impaired intestinal function, and immunity of the small intestine were also observed. Individually, a DHA-enriched diet demonstrated a protective effect against 5-FU damage with longer small intestine mucosal and crypt lengths, greater DAO activity, and higher IgA concentrations, whereas the EPA-enriched diet resulted in decreased inflammatory cytokine concentrations in both plasma and small intestine and expression of apoptosis target genes. CONCLUSIONS: In conclusion, a diet enhanced with EPA and DHA results in synergism protecting against the detrimental effects of 5-FU and limiting chemotherapy induced mucosal impairment.