The Journal of pharmacology and experimental therapeutics
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J. Pharmacol. Exp. Ther. · May 2008
Thioredoxin-1 ameliorates cigarette smoke-induced lung inflammation and emphysema in mice.
Cigarette smoking is associated with the development of inflammatory lung diseases representing major health problems world-wide. We hypothesized that the redox-regulating molecule thioredoxin-1 (TRX), which shows anti-inflammatory, antioxidative, and antiapoptotic effects, could be induced by cigarette smoke (CS) and contribute to protect against CS-induced inflammation and lung destruction. In an acute study, human TRX transgenic mice and C57BL6/J mice were exposed to mainstream CS for 3 days. ⋯ These pathological changes were significantly suppressed in TRX-transgenic mice. In conclusion, TRX induction ameliorated CS-induced lung inflammation and emphysema in mice. TRX-1 may therefore play a preventive or therapeutic role in lung inflammatory disorders such as chronic obstructive pulmonary disease.
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J. Pharmacol. Exp. Ther. · May 2008
First in vivo evidence for a functional interaction between chemokine and cannabinoid systems in the brain.
Growing evidence supports the idea that in addition to their well established role in the immune system, chemokines might play a role in both normal and pathological brain function, and the chemokine network could interact with other neuromodulators. The chemokine stromal cell-derived growth factor (SDF)-1alpha/CXCL12, a member of the CXC chemokine family, was tested for its possible effect on the analgesic responses of the cannabinoid receptor agonist aminoalkylindole 4,5-dihydro-2-methyl-4-(4-morpholinylmethyl)-1-(1-naphthalenyl-carbonyl)-6H-pyrrolo-[3,2,1ij]quinolin-6-one [(+)-WIN 55,212-2, hereafter WIN 55,212-2] at the level of the periaqueductal gray (PAG), a brain region critical to the processing of pain signals, and a primary site of action of many analgesic compounds. The administration of WIN 55,212-2 (0.1-0.4 microg/microl) into the PAG resulted in antinociception in a dose-dependent manner. ⋯ Pretreatment with SDF-1alpha/CXCL12 (100 ng) caused a reduction in antinociceptive responses of WIN 55,212-2. The inhibitory effect of SDF-1alpha/CXCL12 on WIN 55,212-2-induced antinociception was reversed by octahydrochloride [corrected] hydrate (AMD 3100) (10-50 ng), an antagonist of the SDF-1alpha/CXCL12, acting at its receptor, CXCR4. This study reports the first in vivo evidence of a functional interaction between chemokine and cannabinoid systems in the brain, showing that the activation of SDF-1alpha/CXCL12 receptors (CXCR4) in the PAG interferes with the analgesic effects of WIN 55212-2.
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J. Pharmacol. Exp. Ther. · May 2008
Comparative StudyUnexceptional seizure potential of tramadol or its enantiomers or metabolites in mice.
Tramadol is one of the most widely used centrally acting analgesics worldwide. Because of its multimodal analgesic mechanism (opioid plus nonopioid), the adverse effects profile of tramadol, similar to its analgesic profile, can be atypical compared with single-mechanism opioid analgesics. The comparison is often favorable (e.g., less respiratory depression or abuse), but it is sometimes cited as unfavorable in regard to seizure potential. ⋯ The relative potency of tramadol to opioids was not altered by quinidine (an inhibitor of CYP4502D6), noxious stimulus (48 degrees C hot-plate), multiple dosing, or in reserpinized mice. Tramadol seizures were increased by naloxone, principally at high tramadol doses and due to an effect on the (-)enantiomer that overcame the opposite effect on the (+)enantiomer. No synergistic effect on seizure induction was observed between concomitant tramadol and codeine or morphine.
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J. Pharmacol. Exp. Ther. · May 2008
In vivo activation of peroxisome proliferator-activated receptor-delta protects the heart from ischemia/reperfusion injury in Zucker fatty rats.
Peroxisome proliferator-activated receptor (PPAR)-delta is a transcription factor that belongs to the PPAR family. PPAR-delta is abundantly expressed in the heart, and its role in the heart is largely unknown. We tested whether pharmacological activation of PPAR-delta protects the heart from ischemia/reperfusion (I/R) injury in male Zucker fatty rats, a rodent model of obesity and dyslipidemia. ⋯ GW0742 differentially regulated Bcl family members, favoring cell survival, and attenuated I/R-induced cardiac mitochondrial damage. In addition, GW0742 treatment augmented the cardiac Akt signaling pathway, as reflected by enhanced phospho-3-phosphoinositide-dependent kinase-1 and p-Akt. The results indicate that activation of PPAR-delta protected the heart from I/R injury in Zucker fatty rats, and multiple mechanisms including amelioration of lipotoxicity, anti-inflammation, and up-regulation of prosurvival signaling contribute together to the cardioprotection.