title: Folic acid pretreatment prevents the reduction of Na(+),K(+)-ATPase and butyrylcholinesterase activities in rats subjected to acute hyperhomocysteinemia.
abstract: The main objective of the present study was to evaluate the effect of folic acid pretreatment on parietal cortex Na(+),K(+)-ATPase and serum butyrylcholinesterase activities in rats subjected to acute hyperhomocysteinemia. Animals were pretreated daily with an intraperitoneal injection of folic acid (5 mg/kg) or saline from the 22th to the 28th day of age. Twelve hours after the last injection of folic acid or saline, the rats received a single subcutaneous injection of homocysteine (0.6 micromol/g of weight body) or saline and were killed 1h later. Serum was collected and the brain was quickly removed and parietal cortex dissected. Results showed that acute homocysteine administration significantly decreased the activities of Na(+),K(+)-ATPase and butyrylcholinesterase on parietal cortex and serum, respectively. Furthermore, folic acid pretreatment totally prevented these inhibitory effects. We also evaluated the effect of acute homocysteine administration on some parameters of oxidative stress, namely thiobarbituric acid-reactive substances and total thiol content in parietal cortex of rats. No alteration of these parameters were observed in parietal cortex of homocysteinemic animals, indicating that these oxidative stress parameters were probably not responsible for the reduction of Na(+),K(+)-ATPase and butyrylcholinesterase activities. The presented results confirm previous findings that acute hyperhomocysteinemia produces an inhibition of Na(+),K(+)-ATPase and butyrylcholinesterase activities and that pretreatment with folic acid prevents such effects. Assuming that homocysteine might also reduce the activities of these enzymes in human beings, our results support a new potential therapeutic strategy based on folic acid supplementation to prevent the neurological damage found in hyperhomocysteinemia.
authors.affiliation: Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 Anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Matté
authors.forename: Eduardo
authors.initials: E
authors.lastname: Durigon
authors.forename: Francieli M
authors.initials: FM
authors.lastname: Stefanello
authors.forename: Franciele
authors.initials: F
authors.lastname: Cipriani
authors.forename: Moacir
authors.initials: M
authors.lastname: Wajner
authors.forename: Angela T S
authors.initials: AT
authors.lastname: Wyse
mesh_terms: D000818:Animals; D002091:Butyrylcholinesterase / Q000097:blood*; D002540:Cerebral Cortex / Q000201:enzymology; D005492:Folic Acid / Q000627:therapeutic use*; D006710:Homocysteine / Q000008:administration & dosage / Q000378:metabolism; D006801:Humans; D020138:Hyperhomocysteinemia / Q000188:drug therapy / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014803:Vitamin B Complex / Q000627:therapeutic use*
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid; D002091:Butyrylcholinesterase; D000254:Sodium-Potassium-Exchanging ATPase