Increased neuronal nuclear calcium influx in neonatal seizures.
We hypothesized that neonatal seizures lead to increased Ca(2+) influx (nCa(2+)I) in neuronal nuclei of newborn rats and that such increase is nitric-oxide mediated. Neuronal nuclear (45)Ca(2+) influx (nCa(2+)I) was measured in neuronal nuclei of 25 10-day-old male rat-pups newborn brains. They were divided into five groups (n = 5/group). (I) control; (II) hypoxia without seizures; (III) hypoxia with seizures; (IV) kainate, 2 mg/kg intraperitoneal (i.p.)-induced seizures and (V) 7-nitroindazole (7-NINA), 1 mg/kg i.p. pretreated, kainate-induced seizures. nCa(2+)I was significantly (P < 0.05) increased following hypoxia or seizures (hypoxic- or kainate-induced). Post-hypoxic seizures further enhanced nCa(2+)I increase induced by hypoxia (P < 0.05). 7-NINA abated the nCa(2+)I increase induced by kainate. We conclude that (1) kainate or hypoxia-induced seizures in newborn rats modify the neuronal nuclear membrane function, resulting in increased nCa(2+)I, (2) seizures exacerbate the hypoxia-induced increased nCa(2+)I incurred after hypoxia and (3) intranuclear calcium surges during kainate-induced neonatal seizures are nitric oxide-mediated.
Valencia
Ignacio
I
Section of Neurology, Department of Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine, Erie Avenue at Front Street, Philadelphia, PA 19134, USA. Ignacio.Valencia@drexelmed.edu
Mishra
Om P
OP
Fritz
Karen
K
Zubrow
Alan
A
Katsetos
Christos D
CD
Delivoria-Papadopoulos
Maria
M
Legido
Agustín
A
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D004569:Electroencephalography; D017136:Ion Transport; D008297:Male; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D012640:Seizures / Q000378:metabolism*
D002118:Calcium