Reduced cardiac output is associated with decreased mitochondrial efficiency in the non-ischemic ventricular wall of the acute myocardial-infarcted dog

Cardiogenic shock is the leading cause of death among patients hospitalized with acute myocardial infarction （MI）. Understanding the mechanisms for acute pump failure is therefore important. The aim of this study is to examine in an acute MI dog model whether mitochondrial bio-energetic function within non-ischemic wall regions are associated with pump failure. Anterior MI was produced in dogs via ligation of left anterior descending （LAD） coronary artery, that resulted in an infract size of about 30% of the left ventricular wall. Measurements ofhemodynamic status, mitochondrial function, free radical production and mitochondrial uncoupling protein 3 （UCP3） expression were determined over 24 h period. Hemodynamic measurements revealed a 〉 50% reduction in cardiac output at 24 h post infarction when compared to baseline. Biopsy samples were obtained from the posterior non-ischemic wall during acute infarction. ADP/O ratios for isolated mitochondria from non-ischemic myocardium at 6 h and 24 h were decreased when compared to the ADP/O ratios within the same samples with and without palmitic acid （PA）. GTP inhibition of （PA）-stimulated state 4 respiration in isolated mitochondria from the non-ischemic wall increased by 7% and 33% at 6 h and 24 h post-infarction respectively when compared to sham and pre-infarction samples. This would suggest that the mitochondria are uncoupled and this is supported by an associated increase in UCP3 expression observed on western blots from these same biopsy samples. Blood samples from the coronary sinus measured by electron paramagnetic resonance （EPR） methods showed an increase in reactive oxygen species （ROS） over baseline at 6 h and 24 h post-infarction. In conclusion, mitochondrial bio-energetic ADP/O ratios as a result of acute infarction are abnormal within the non-ischemic wall. Mitochondria appear to be energetically uncoupled and this is associated with declining pump function. Free radical production may be associated with the induction of uncoupling proteins in the mitochondria.

Far infrared-emitting ceramics decrease Freund's adjuvant-induced inflammatory hyperalgesia in mice through cytokine modulation and activation of peripheral inhibitory neuroreceptors

Objective： The present study aimed to evaluate the analgesic and anti-inflammatory effects of far infrared-emitting ceramics （cFIRs） in a model of persistent inflammatory hyperalgesia and to elucidate the possible mechanisms of these effects. Methods： Mice were injected with complete Freund＇s adjuvant （CFA） and treated with cFIRs via place- ment on a pad impregnated with cFIRs on the bottom of the housing unit for different periods of time. Mice underwent mechanical hyperalgesia and edema assessments, and tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β） and IL-10 levels were measured. Twenty-four hours after CFA injection and 30 min before cFIR treatment, mice were pretreated with a nonselective adenosinergic antagonist, caffeine, the selective adenosine receptor A antagonist, 1,3-dipropyl-8-cyclopentylxanthine （DPCPX）, the selective cannabinoid receptor type 1 antagonist, AM281, the selective cannabinoid receptor type 2 antagonist, AM630, or the nonselective opioid receptor antagonist, naloxone, and mechanical hyperalge- sia was assessed. Results： cFIRs statistically （P 〈 0.05） decreased CFA-induced mechanical hyperalgesia （82.86 ±5.21）% in control group vs （56.67±9.54）% in cFIR group） and edema （（1699.0 ± 77.8） gm in control group vs （988.7±107.6） gm in cFIR group）, cFIRs statistically （P 〈 0.05） reduced TNF-α （0.478± 0.072） pg/mg of protein in control group vs （0.273 ±0.055） pg/mg of protein in cFIR group） and IL-113 （（95.81 ± 3.95） pg/mg of protein in control group vs （80.61 ±4.71）pg/mg of protein in cFIR group） levels and statistically （P〈 0.05） increased IL-10 （（18.32 ±0.78） pg/mg of protein in control group vs （25.89 ±1.23） pg/mg of protein in cFIR group） levels in post-CFA-injected paws. Peripheral pre-administration of inhibitory neuroreceptor antagonists （caffeine, DPCPX, AM281, AM630 and naloxone） prevented the analgesic effects of cF1Rs （P 〈 0.05）.Conclusion： These data provide additional support for the use of cFIRs in the treatment of painful inflam- matory conditions and contribute to our understanding of the neurobiological mechanisms of the ther- apeutic effects of cFIRs.