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Objective To establish a modified induction method for differentiation of rat pancreatic ductal stem cells (rPDSCs) to form islet-like cells. Methods All-trans retinic acid(ATRA) was added at 2, 4, 6 and 8 jjimol/L in the basal culture medium DMEM/F12 + 10% FBS + 1% penicillin/1% streptomycin to induce the differentiation of rPDSCs to form islet-like cells in vitro, and the optimal induction concentration of ATRA was screened. Based on the optimal ATRA induction concentration, rPDSCs were then induced to form islet-like cells in vitro by matrigel culture, suspension culture or hanging drop culture, respectively, to screen the optimal induction culture method . Cell morphology, dithizone(DTZ) staining, cell immunofluorescence staining, Real-time PCR and ELISA were used to detect the induced islet-like cells. Results Compared with the control group, 6 (jumol/L ATRA and matrigel culture were the best in the basic culture medium. After 28 days of induction, the cells enriched and differentiated to form islet-like spherical cell clusters; DTZ staining was positive; Pancreatic duodenal homeobox-1 (Pdxl) and insulin were expressed at gene and protein levels, respectively; Glucose stimulation, release insulin and C-peptide, showed glucose concentration dependent. Conclusion The in vitro differentiation of rPDSCs to form islet-like cells could be successfully induced by using 6 |xmol/L ATRA + DMEM/F12+10% FBS+1% double antibody under matrigel culture method in the present study.
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The effect of curcumin, a dietary antioxidant was studied against kainic acid (KA)-induced seizures and on markers of oxidative stress. Rats were administered KA (10 mg/kg, ip) and observed for behavioral changes, incidence and latency of convulsions and mortality over four hours. The rats were thereafter sacrificed for estimation of oxidative stress parameters; malondialdehyde (MDA) and glutathione (GSH). Curcumin was administered 30 min before KA at doses of 50, 100 and 200 mg/kg, ip. KA induced long-lasting seizures and associated symptoms. The brain level of MDA was significantly (P<0.05) raised after KA administration (536±44 nmol/g wet tissue) as compared to saline treated group (200±36 nmol/g wet tissue) and significantly decreased the levels of GSH. Pretreatment with curcumin (100 and 200 mg/kg, ip) significantly increased the latency of seizures (120+20 min and 115±5.7 min respectively) as compared to the vehicle treated KA group. Curcumin (100 and 200 mg/ kg, ip) significantly prevented the increase in MDA levels and ameliorated the fall in glutathione. Curcumin at the dose of 50 mg/kg had no effect on any of oxidative stress parameters. The study reports the potential antiepileptic effect of antioxidant curcumin.
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In the present study, effects of intracerebroventricular (icv) administration of histamine, mepyramine (H1-receptor antagonist) and famotidine (H2-receptor antagonist) have been investigated on the formalin test in rats. Subcutaneous injection of formalin (50 μl, 1%) into the ventral surface of the left hind paw produced a marked biphasic pain response (first phase: 0–5 min and second phase: 15–45 min). All the performed treatments did not significantly influence the first phase of pain. Histamine at the doses of 10 and 40 μg and mepyramine and famotidine at the same doses of 20 and 80 μg, significantly (P<0.05) decreased the late phase of formalin-induced pain. Pretreatments with mepyramine and famotidine at the same dose of 80 μg, significantly (P<0.05) prevented the histamine (40 μg)-induced antinociception. These results indicate that brain histamine produces antinociception, and both central H1 and H2 receptors may involve in the histamine-induced antinociception in the formalin test in rats.