title: Cyclic GMP in sequential samples of lumbar CSF in man.
abstract: cGMP was measured in 15 and 20 sequential 2 ml samples of CSF withdrawn by lumbar puncture in two patients respectively who were recumbent for at least 8 hours. cGMP showed a significant linear increase in concentration with progressive sampling (r = 0.70, p less than 0.01; r = 0.59, p less than 0.01, respectively). These data indicate (a) the presence of a rostrocaudal gradient in CSF cGMP (b) recumbency and volume of CSF are important variables to consider in clinical studies (c) the cerebellum may be a source of cGMP in lumbar CSF.
mesh_terms: D000368:Aged; D006152:Cyclic GMP / Q000134:cerebrospinal fluid*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D006152:Cyclic GMP