We determined the effects of cyclooxygenase-1 (COX-1; SC-560), COX-2 (SC-58125), and inducible nitric oxide synthase (iNOS; 1400W) inhibitors on atorvastatin (ATV)-induced myocardial protection and whether iNOS mediates the ATV-induced increases in COX-2. Sprague-Dawley rats received 10 mg ATV.kg(-1).day(-1) added to drinking water or water alone for 3 days and received intravenous SC-58125, SC-560, 1400W, or vehicle alone. Anesthesia was induced with ketamine and xylazine and maintained with isoflurane. Fifteen minutes after intravenous injection rats underwent 30-min myocardial ischemia followed by 4-h reperfusion [infarct size (IS) protocol], or the hearts were explanted for biochemical analysis and immunoblotting. Left ventricular weight and area at risk (AR) were comparable among groups. ATV reduced IS to 12.7% (SD 3.1) of AR, a reduction of 64% vs. 35.1% (SD 7.6) in the sham-treated group (P < 0.001). SC-58125 and 1400W attenuated the protective effect without affecting IS in the non-ATV-treated rats. ATV increased calcium-independent NOS (iNOS) [11.9 (SD 0.8) vs. 3.9 (SD 0.1) x 1,000 counts/min; P < 0.001] and COX-2 [46.7 (SD 1.1) vs. 6.5 (SD 1.4) pg/ml of 6-keto-PGF(1alpha); P < 0.001] activity. Both SC-58125 and 1400W attenuated this increase. SC-58125 did not affect iNOS activity, whereas 1400W blocked iNOS activity. COX-2 was S-nitrosylated in ATV-treated but not sham-treated rats or rats pretreated with 1400W. COX-2 immunoprecipitated with iNOS but not with endothelial nitric oxide synthase. We conclude that ATV reduced IS by increasing the activity of iNOS and COX-2, iNOS is upstream to COX-2, and iNOS activates COX-2 by S-nitrosylation. These results are consistent with the hypothesis that preconditioning effects are mediated via PG.

Background-Both statins and thiazolidinediones have antiinflammatory properties. However, the exact mechanisms underlying these effects are unknown. We investigated whether atorvastatin (ATV) and pioglitazone (PIO) increase the myocardial content of lipoxin-A 4 and 15(R)-epi-lipoxin-A 4 (15-epi-LXA 4 ), both arachidonic acid products with strong antiinflammatory properties. Methods and Results-In experiment 1, rats received 3-day pretreatment with water; PIO 2, 5, or 10 mg · kg Ϫ1 · d Ϫ1 ; ATV 2, 5, or 10 mg · kg Ϫ1 · d

We assessed 1) whether pretreatment before ischemia with pioglitazone (Pio) limits infarct size (IS) and whether this protective effect is due to nitric oxide synthase (NOS) and/or prostaglandin production, as has been shown for atorvastatin (ATV); and 2) whether Pio and ATV have synergistic effects on myocardial protection. Sprague-Dawley rats received oral ATV (10 mg ⅐ kg Ϫ1 ⅐ day Ϫ1 ), Pio (10 mg ⅐ kg Ϫ1 ⅐ day Ϫ1 ), their combination (Pio ϩ ATV), or water alone for 3 days. Additional rats received Pio (10 mg ⅐ kg Ϫ1 ⅐ day Ϫ1 ) for 3 days and intravenous SC-58125 [a cyclooxygenase-2 (COX-2) inhibitor] or SC-560 (a COX-1 inhibitor) 15 min before ischemia. Rats underwent 30 min of myocardial ischemia and 4 h of reperfusion, or hearts were harvested for analysis. IS in the Pio and in the ATV groups was significantly smaller than in the sham-treated group. IS in the Pio ϩ ATV group was smaller than in all other groups (P Ͻ 0.001 vs. each group). The protective effect of Pio was abrogated by SC-58125 but not by SC-560. Pio, ATV, and Pio ϩ ATV increased the expression and activity of cytosolic phospholipase A 2 (cPLA2) and COX-2. ATV increased phosphorylatedAkt, phosphorylated-endothelial NOS (P-eNOS), inducible NOS, and COX-2 levels. In contrast, Pio caused an insignificant increase in myocardial levels of phosphorylated-Akt but did not change P-eNOS and iNOS expression. In conclusion, the IS-limiting effects of Pio and ATV involve COX-2. However, the upstream steps differ. ATV induced eNOS phosphorylation and iNOS, cPLA 2, and COX-2 expression, whereas Pio induced mainly the expression and activity of cPLA 2. The effects of Pio and ATV were additive. infarct size; thiazolidinediones; statins; cyclooxygenase-2; cytosolic phospholipase A2; nitric oxide synthase; protein kinase Akt; phosphatase and tensin homologue deleted on chromosome 10, anti-Src homology 2-containing inositol phosphatase-2

In this study, we investigated the role of Trypanosoma cruzi invasion and inflammatory processes in reactive oxygen species (ROS) production in mouse atrial cardiomyocyte line (HL-1) and primary adult rat ventricular cardiomyocytes. Cardiomyocytes were incubated with T. cruzi (Tc) trypomastigotes, Tc lysate (TcTL) or Tc secreted proteins (TcSP) for 0-72 h, and ROS measured by amplex red assay. Cardiomyocytes infected by T. cruzi (but not those incubated with TcTL or TcSP) exhibited a linear increase in ROS production during 2-48 h post-infection (max.18-fold increase) which was further enhanced by recombinant cytokines (IL-1β, TNF-α and IFN-γ). We observed no increase in NADPH oxidase, xanthine oxidase, and myeloperoxidase activities, and specific inhibitor of these enzymes did not block the increased rate of ROS production in infected cardiomyocytes. Instead, the mitochondrial membrane potential was perturbed, and resulted in inefficient electron transport chain (ETC) activity, and enhanced electron leakage and ROS formation in infected cardiomyocytes. HL-1 rho (ρ) cardiomyocytes lacked a functional ETC, and exhibited no increase in ROS formation in response to T. cruzi. Together, these results demonstrate that invasion by T. cruzi and inflammatory milieu affect mitochondrial integrity and contribute to electron transport chain inefficiency and ROS production in cardiomyocytes.

ATV and CIL have synergistic effect on eNOS phosphorylation and IS reduction. By increased activation of eNOS, CIL may augment the pleiotropic effects of statins.