Participation of mast cells (MCs) in paw edema induced by <i>Micrurus lemniscatus</i> venom.

<p>(A) Groups of rats were treated with compound 48/80 (0.1 to 5.0 mg/mL i.p. twice a day for 5 consecutive days) or an equal volume of vehicle i.p. (control) before MLV injection (5 μg/paw). Edema was evaluated using a plethysmometer at the time points shown. Data are expressed as % increase in paw volume compared with the control paw. (B) Degranulation of mesenteric mast cells was assessed 15 min after venom injection by counting the percentage of cells with extruded granules in the histological preparation. (C, D) Toluidine blue staining of mesenteric mast cells treated with apyrogenic saline (C) or MLV (2.8 μg/g) (D). The mesentery had minimal mast cell degranulation after i.p. injection with apyrogenic saline and extensive mast cell degranulation after injection with MLV. Values are the mean ± SEM of five animals. * <i>p</i> < 0.05 compared with control group.</p

Effect of biogenic amine-receptor antagonists on paw edema induced by <i>Micrurus lemniscatus</i> venom.

<p>Groups of animals were treated with promethazine (5 mg/kg, i.p.) (an H₁ receptor antagonist), thioperamide (5 mg/kg, i.p.) (an H₃R/H₄R receptor antagonist) or methysergide (5 mg/kg, i.p.) (a nonselective 5-HT receptor antagonist) 30 min before intraplantar injection of MLV (5 μg/paw). The increase in volume of each paw (edema) was measured using a plethysmometer. Data were calculated as the difference between both paws and are expressed as a % increase in paw volume. Values are the mean ± SEM of five animals. * <i>p</i> < 0.05 compared with control group.</p

Participation of mast cells (MCs) in paw edema induced by <i>Micrurus lemniscatus</i> venom.

<p>(A) Groups of rats were treated with compound 48/80 (0.1 to 5.0 mg/mL i.p. twice a day for 5 consecutive days) or an equal volume of vehicle i.p. (control) before MLV injection (5 μg/paw). Edema was evaluated using a plethysmometer at the time points shown. Data are expressed as % increase in paw volume compared with the control paw. (B) Degranulation of mesenteric mast cells was assessed 15 min after venom injection by counting the percentage of cells with extruded granules in the histological preparation. (C, D) Toluidine blue staining of mesenteric mast cells treated with apyrogenic saline (C) or MLV (2.8 μg/g) (D). The mesentery had minimal mast cell degranulation after i.p. injection with apyrogenic saline and extensive mast cell degranulation after injection with MLV. Values are the mean ± SEM of five animals. * <i>p</i> < 0.05 compared with control group.</p

Effect of capsaicin and tachykinin NK₁- and NK₂-receptor antagonists (SR14033 and SR 48968, respectively) on edema induced by <i>Micrurus lemniscatus</i> venom.

<p>Groups of animals were treated with capsaicin (15, 30 and 50 mg/kg, s.c.) for 4 consecutive days to deplete substance P from sensitive primary afferent neurons or NK₁- or NK₂ receptor antagonists. Both SR 140333 (1 nmol/paw) and SR 48968 (10 nmol/paw) were co-injected i.pl. with MLV (5 μg/paw). The increase in volume of each paw (edema) was measured using a plethysmometer. Results were calculated as the difference between hind paws and are expressed as a % increase in paw volume. Values are the mean ± SEM of five animals. * p < 0.05 compared with control group.</p

Effect of bradykinin BK₂-receptor antagonist (HOE 140) on paw edema induced by <i>Micrurus lemniscatus</i> venom.

<p>Groups of animals were treated with HOE 140 (5 μg/paw) concomitantly with MLV (5 μg/paw, i.pl.). The increase in volume of each paw (edema) was measured using a plethysmometer. Results were calculated as the difference between hind paws and are expressed as a % increase in paw volume. Values are the mean ± SEM of five animals. None of the results were statistically significant.</p

Time course of rat paw edema induced by selected doses of <i>Micrurus lemniscatus</i> venom.

<p>Increased paw volume was determined at various time points after intraplantar injection of MLV (1–10 μg/paw) into one paw and apyrogenic saline into the contralateral paw (control paw). The increase in volume of each paw (edema) was measured using a plethysmometer. Differences between paws were expressed as a % increase in paw volume. Values are the mean ± SEM of five animals. * <i>p</i> < 0.05 compared with MLV (1 μg/paw).</p

TLR2 and Myd88 signaling pathways are involved in MT-III-induced prostanoid biosynthesis and COX-2 protein expression.

<p>Wild type (WT) or TLR2^−/− or MyD88^−/− peritoneal macrophages were incubated with MT-III (0.4 μM) or RPMI (control) for 6 h. PGE₂ (A), PGD₂ (B) and PGJ₂ (C) concentrations were quantified in culture supernatants by EIA commercial kits; (D) Western blotting immunoreactive bands of COX-2 and β-actin (loading control) representative of at least three samples/experimental group; (E) Densitometric analysis of immunoreactive COX-2 band intensities. Densities (in arbitrary units) were normalized with those of β-actin. Results are expressed as mean ± SEM from 3–6 animals. *<i>p</i><0.05 as compared with control cells; ^#<i>p</i><0.05 as compared with MT-III-stimulated cells.</p

TLR2 and MyD88 are essential for MT-III-induced perilipin-2 (PLIN2) subcellular distribution.

<p>Wild Type (WT), TLR2^−/− or MyD88^−/− peritoneal macrophages were incubated with RPMI (control) or MT-III (0.4 μM) for 6 h and labeled for both lipid droplets (fluorescent Nile red) and anti-PLIN2 (FITC-conjugated immunocomplex). Merged image shows localization of PLIN2 to lipid droplets in WT macrophages. Cell nuclei were stained with propidium iodide. IgG control was included and showed negative stain. The micrographs are representative of at least three samples/experimental group.</p

TLR2 and MyD88 signaling pathways are relevant for MT-III-induced IL-1β and IL-10 release.

<p>Wild type (WT) or TLR2^−/− or MyD88^−/− peritoneal macrophages were incubated with MT-III (0.4 μM) or RPMI (control) for 6 h. IL-1β (A) and IL-10 (B) concentrations were quantified in culture supernatants by EIA commercial kits. Results are expressed as mean ± SEM from 3–6 animals. *<i>p</i><0.05 as compared with control group; ^#<i>p</i><0.05 as compared with MT-III- stimulated WT cells.</p

TLR2 and MyD88 are required for lipid droplet formation, but only MyD88 is relevant to perilipin-2 protein expression induced by MT-III.

<p>Wild type (WT) or TLR2^−/− or MyD88^−/− peritoneal macrophages were incubated either with MT-III (0.4 μM) or RPMI (control) for 6 or 12 h. (A) Lipid droplets numbers; (B) Western blotting immunoreactive bands of perilipin-2 (PLIN2) and β-actin (loading control); (C) Densitometric analysis of immunoreactive PLIN2 band intensities. Densities (in arbitrary units) were normalized with those of β-actin. Results are expressed as mean ± SEM from 3–6 animals. *<i>p</i><0.05 as compared with control group; #<i>p</i><0.05 as compared with MT- III- stimulated WT cells.</p