title: Modifications in muscarinic, dopaminergic and serotonergic receptors concentrations in the hippocampus and striatum of epileptic rats.
abstract: The present study was undertaken in order to investigate the muscarinic (M(1)), dopaminergic (D(1) and D(2)) and serotonergic (5-HT(2)) receptors densities in hippocampus and striatum of Wistar rats after status epilepticus (SE) induced by pilocarpine. The control group was treated with 0.9% saline. An other group of rats received pilocarpine (400 mg/kg, s.c.) and both groups were sacrificed 1 h after treatment. The results have shown that pilocarpine administration and resulting SE produced a downregulation of M(1) receptor in hippocampus (41%) and striatum (51%) and an increase in the dissociation constant (K(d)) values in striatum (42%) alone. In both areas the 5-HT(2) receptor density remained unaltered, but a reduction (50%) and an increase (15%) in the K(d) values were detected in striatum and hippocampus, respectively. D(1) and D(2) receptor densities in hippocampus and striatum remained unaltered meanwhile K(d) values for D(1) receptor declined significantly, 33% in hippocampus and 26% in striatum. Similarly, K(d) values for D(2) decreased 55% in hippocampus and 52% in striatum. From the preceding results, it is clear that there is a possible relation between alterations in muscarinic receptor density and others systems studied as well as they suggest that changes in dissociation constant can be responsible for the establishment of pilocarpine-induced SE by altering the affinity of neurotransmitters such as acetylcholine, dopamine and serotonine.
authors.affiliation: Department of Physiology and Pharmacology, Laboratory of Neuropharmacology, School of Medicine, Federal University of Ceará, Rua Cel. Nunes de Melo 1127, Fortaleza 60431-970, CE, Brazil. rivmendes@bol.com.br
authors.forename: Rivelilson
authors.initials: R
authors.lastname: Mendes de Freitas
authors.forename: Lissiana M V
authors.initials: LM
authors.lastname: Aguiar
authors.forename: Silvânia M M
authors.initials: SM
authors.lastname: Vasconcelos
authors.forename: Francisca C F
authors.initials: FC
authors.lastname: Sousa
authors.forename: Glauce S B
authors.initials: GS
authors.lastname: Viana
authors.forename: Marta M F
authors.initials: MM
authors.lastname: Fonteles
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D003342:Corpus Striatum / Q000378:metabolism*; D004195:Disease Models, Animal; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D010862:Pilocarpine / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*
chemical_list: D011954:Receptors, Dopamine; D011976:Receptors, Muscarinic; D011985:Receptors, Serotonin; D010862:Pilocarpine