title: Nitric oxide synthase expression in the cerebral cortex of patients with epilepsy.
abstract: OBJECTIVE
  Nitric oxide (NO), a short-lived radical synthesized from L-arginine by activation of the enzyme nitric oxide synthase (NOS), has been implicated in the pathophysiology of epilepsy by some investigators. However, the current data about NO and NOS in epilepsy are controversial and are derived only from animal models of epilepsy. In this study we investigated possible changes in NOS expression in the cerebral cortex of patients with epilepsy.
  
  
  METHODS
  Qualitative and quantitative parameters of the immunolabeling pattern of the neuronal, endothelial, and inducible isoforms of NOS were analyzed in biopsy material obtained from patients with short and long seizure history and from patients without epilepsy.
  
  
  RESULTS
  The comparative study showed that in the cerebral cortex of patients with epilepsy, particularly in those with a long seizure history, the number and labeling intensity of NOS-positive neurons increased, and that a subpopulation of nonpyramidal GABAergic neurons (type II NOS neurons) was responsible for this phenomenon.
  
  
  CONCLUSIONS
  The fact that NOS upregulation is more evident in patients with a long seizure history suggests that this is a consequence of seizures, acting probably as an adaptative response to the sustained release of excitatory amino acids.
authors.affiliation: Department of Anatomy, Pathology and Histology, Faculty of Medicine, University of La Laguna, Tenerife, Spain. tgonhern@ull.es
authors.forename: T
authors.initials: T
authors.lastname: González-Hernández
authors.forename: V
authors.initials: V
authors.lastname: García-Marín
authors.forename: M M
authors.initials: MM
authors.lastname: Pérez-Delgado
authors.forename: M L
authors.initials: ML
authors.lastname: González-González
authors.forename: N
authors.initials: N
authors.lastname: Rancel-Torres
authors.forename: L
authors.initials: L
authors.lastname: González-Feria
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002540:Cerebral Cortex / Q000737:chemistry / Q000201:enzymology*; D002648:Child; D004727:Endothelium / Q000201:enzymology; D004827:Epilepsy / Q000201:enzymology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism*; D020033:Protein Isoforms
chemical_list: D020033:Protein Isoforms; D019001:Nitric Oxide Synthase