European journal of pharmacology
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Neutrophils are innate immune cells in chronic inflammatory diseases including chronic obstructive pulmonary disease (COPD) and can be attracted to the site of inflammation via the collagen breakdown product N-acetyl Proline-Glycine-Proline (N-Ac-PGP). To elucidate whether CXCR2 is involved in N-Ac-PGP-induced neutrophil migration and activation, studies using specific antagonists were performed in vivo. N-Ac-PGP and keratinocyte cell-derived chemokine (KC; CXCL1) were administered in C57Bl/6 mice via oropharyngeal aspiration. ⋯ In conclusion, neutrophil migration induced by N-Ac-PGP is mediated via direct CXCR2 interaction. The N-Ac-PGP-induced release of CXCL1 is independent of CXCR2. Related to the maximal effect of CXCL1, N-Ac-PGP is more potent at inducing neutrophil migration in the pulmonary tissue than into the bronchoalveolar lavage fluid, or N-ac-PGP may be more potent at inducing MPO levels in the lung tissue.
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The stimulation of spinal cannabinoid type 2 (CB(2)) receptors is a suitable strategy for the alleviation of experimental pain symptoms. Several reports have described the up-regulation of spinal cannabinoid CB(2) receptors in neuropathic settings together with the analgesic effects derived from their activation. Besides, we have recently reported in two murine bone cancer models that the intrathecal administration of cannabinoid CB(2) receptor agonists completely abolishes hyperalgesia and allodynia, whereas spinal cannabinoid CB(2) receptor expression remains unaltered. ⋯ The analgesic effects induced by both agonists were counteracted by the coadministration of the selective cannabinoid CB(2) receptor antagonist SR144528, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide, (5 μg) but not by the cannabinoid CB(1) receptor antagonist AM251, N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide, (10 μg). The effects induced by AM1241 were also inhibited by the coadministration of the opioid receptor antagonist, naloxone (1 μg). These results demonstrate that effective analgesia can be achieved in chronic inflammatory settings through the stimulation of spinal cannabinoid CB(2) receptors even if this receptor population is not up-regulated.
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Nerve injury, diabetes and cancer therapies are often associated with painful neuropathy. The mechanism underlying neuropathic pain remains poorly understood. The current therapies have limited efficacy and are associated with dose-limiting side effects. ⋯ In the diabetic and chemotherapy induced neuropathic models compound exerted antinociceptive activity and reduction in the mechanical hyperalgesia was observed. A-366833 dose dependently attenuated mechanical hyperalgesia in complete Freund's adjuvant induced inflammatory pain model. These results demonstrated broad-spectrum antinociceptive properties of A-366833 in both neuropathic and inflammatory pain models.
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Luteolin occurs in a variety of plants and possesses antioxidant and anti-inflammatory properties. However, its role in protection against ischemia-reperfusion injury in Sprague-Dawley rats has not been elucidated. In the present study, we tested the contractile function of left ventricular cardiomyocytes with different concentrations of luteolin: 0.5, 1.5, 2.5 and 5.0 μg/ml after simulated. ⋯ Luteolin inhibited the activation of Caspase3 after ischemia-reperfusion in cardiomyocytes. Furthermore, luteolin at 10.0 μg/ml improved ischemia-reperfusion induced myocardial function, by improving heart rate, +dp/dt(max) and -dp/dt(max), and also limiting the decline of left ventricular systolic pressure (LVSP) and elevation of left ventricular end-diastolic pressure (LVEDP) to some extent. Our results demonstrated that luteolin prevents ischemia-reperfusion injury by reducing necrosis and apoptosis in rat cardiomyocytes.
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Most of renin-angiotensin system (RAS) gene polymorphisms have not yet been studied in the Iranian population. In the present study, the frequencies of common polymorphisms in the RAS genes, including angiotensin-converting enzyme (ACE) insertion/deletion (I/D) and three single-nucleotide polymorphisms (SNPs), i.e., A-240T, T-93C and A2350G, angiotensinogen M235T, angiotensin II receptor type 1 A1166C and angiotensin II receptor type 2 C3123A variants were determined in DNAs extracted from venous blood of 104 healthy Iranian volunteers. Genotyping was performed by PCR-RFLP method. ⋯ In conclusion, combined polymorphisms of A-240T and A2350G seem to affect serum ACE level as well as diastolic blood pressure in our study population. However, it also might be hypothesized that they are in strong linkage disequilibrium with other functional mutations not studied yet. Our findings revealed that gene interactions can play an important role in various biological conditions.