بررسي تاثير تخليه مركزي و محيطي سيستم سروتونرژيك مركزي بر التهاب محيطي ايجاد شده توسط كاراژنين در پاي موش صحرايي

Effects of central and peripheral depletion of serotonergic system on carrageenan-induced paw oedema

The role of serotonergic system was investigated on peripheral inflammation induced by intraplantary injection of carrageenan. Para-chlorophenylalanine (pCPA) was administered intracerebroventriculary (50, 100 ug/rat) or intraperitoneally (150 mg/kg, 3 days) and inflammation was induced by injection of carrageenan, 2 hours and 1 day later, respectively. Paw oedema was decreased significantly in pCPA-treated (100 (Gama)g/rat, i.c.v.) rats compared to control groups. Injection of exogenous serotonin (i.c.v.) by dose of 0.70 nmol/l0(Gama)l/rat, but not the dose of 0.35 nmol/l0(Gama)l/rat, 15 min after induction of inflammation completely reversed the anti-inflammatory effects of pCPA. Myeloperoxidase activity in inflamed paws were reduced significantly in groups who received (either i.c.v. or i.p.) pCPA compared to controls. Exogenous serotonin (0.70 nmol/l0(Gama)l/rat) reduced inflammatory response when injected (i.c.v.) 30 min before or 30 min after the induction of inflammation. Injection of serotonin at the time of induction of inflammation had no inflammatory/anti-inflammatory effect. These results suggest that serotonin, as a neurotransmitter in central nervous system, may be involved in modulating peripheral inflammation.