Early life LiCl-pilocarpine-induced status epilepticus reduces acutely hippocampal glutamate uptake and Na+/K+ ATPase activity.
Status epilepticus-induced hippocampal neuronal loss is mainly associated with excitotoxicity induced by increased levels of extracellular glutamate which is normally neutralized by high-affinity uptake mechanism. The energy source for the glutamate uptake is the electrochemical Na(+) gradient maintained by Na(+)/K(+) ATPase pump. In this study, we investigated the effect of early-life-induced status epilepticus on hippocampal Na(+)/K(+) ATPase activity and glutamate uptake. Rat pups 15 days old were injected i.p. with LiCl (3 mEq/kg) 12-18 h prior to s.c. pilocarpine administration (60 mg/kg). Hippocampal Na(+)/K(+) ATPase activity and glutamate uptake were evaluated 1.5, 12 and 24 h after SE induction. LiCl-pilocarpine-induced SE decreased Na(+)/K(+) ATPase activity and glutamate uptake by 42 and 38%, respectively, 1.5 h after SE induction. However, 12 and 24 h after SE induction the pump activity and glutamate uptake returned to control levels. SE early in life increased hippocampal number of degenerating neurons in the CA1 subfield and dentate gyrus 24 h after SE induction. In conclusion, SE induced early in life causes short-term disruption in hippocampal Na(+)/K(+) ATPase activity and glutamate uptake, which may be related to neuronal death found in CA1 subfield.
de Oliveira
Diogo Losch
DL
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. losch@ufrgs.br
Bavaresco
Caren
C
Mussulini
Ben Hur
BH
Fischer
Alice
A
Souza
Diogo Onofre
DO
Wyse
Angela T S
AT
Wofchuk
Susana
S
D000818:Animals; D003292:Convulsants / Q000633:toxicity; D004789:Enzyme Activation / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D018021:Lithium Chloride / Q000633:toxicity; D008297:Male; D009410:Nerve Degeneration / Q000378:metabolism / Q000473:pathology; D010862:Pilocarpine / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013226:Status Epilepticus / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology
D003292:Convulsants; D010862:Pilocarpine; D018698:Glutamic Acid; D000254:Sodium-Potassium-Exchanging ATPase; D018021:Lithium Chloride