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 microg/rat) or intraperitoneally (150 mg/kg, 3 days) and 2 or 24 h later, respectively, inflammation was induced by injection of carrageenan. Paw oedema was decreased significantly in PCPA-treated (100 microg/rat, i.c.v.) rats compared to control groups. Injection of exogenous serotonin (i.c.v.) by dose of 0.70 nmol/10 microl/rat, but not the dose of 0.35 nmol/10 microl/rat, 15 min after induction of inflammation completely reversed the anti-inflammatory effects of PCPA. Myeloperoxidase activity in inflamed paws was reduced significantly in groups received PCPA (either i.c.v. or i.p.) compared to controls. Exogenous serotonin (0.70 nmol/10 microl/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.
Maleki
Nasrin
N
Department of Pharmacology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz 51664, Iran. malekins@tbzmed.ac.irv
Nayebi
Alireza Mohajjel
AM
Garjani
Alireza
A
D000818:Animals; D002351:Carrageenan; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004487:Edema / Q000201:enzymology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D010134:Fenclonine / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006614:Hindlimb / Q000187:drug effects / Q000473:pathology; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*
D012702:Serotonin Antagonists; D012701:Serotonin; D002351:Carrageenan; D009195:Peroxidase; D010134:Fenclonine