Effects of phosphodiesterase inhibition on cortical spreading depression and associated changes in extracellular cyclic GMP

Biochem Pharmacol. 2004 Apr 15;67(8):1619-27. doi: 10.1016/j.bcp.2003.12.029.


Cortical spreading depression (CSD) is a temporary disruption of local ionic homeostasis that propagates slowly across the cerebral cortex, and may contribute to the pathophysiology of stroke and migraine. Previous studies demonstrated that nitric oxide (NO) formation promotes the repolarisation phase of CSD, and this effect may be cyclic GMP (cGMP)-mediated. Here, we have examined how phosphodiesterase (PDE) inhibition, either alone or superimposed on NO synthase (NOS) inhibition, alters CSD and the associated changes in extracellular cGMP. Microdialysis probes incorporating an electrode were implanted into the frontoparietal cortex of anaesthetised rats for quantitative recording of CSD, pharmacological manipulations, and dialysate sampling for cGMP measurements. CSD was induced by cathodal electrical stimulation in the region under study by microdialysis. Extracellular cGMP increased, but only slightly, during CSD. Perfusion of either zaprinast or sildenafil through the microdialysis probe, at concentrations that inhibited both PDE5 and PDE9 (and possibly other PDE), increased significantly extracellular cGMP. Unexpectedly, these levels remained high when NOS was subsequently inhibited with N(omega)-nitro-l-arginine methyl ester hydrochloride (l-NAME, 1mM). The most interesting pharmacological effect on CSD was obtained with sildenafil. This drug altered neither CSD nor the subsequent characteristic effect of NOS inhibition, i.e. a marked widening of CSD. The fact that NOS inhibition still widened CSD in the presence of the high extracellular levels of cGMP associated with PDE inhibition, suggests that NO may promote CSD recovery, independently of cGMP formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3',5'-Cyclic-GMP Phosphodiesterases / antagonists & inhibitors
  • 3',5'-Cyclic-GMP Phosphodiesterases / metabolism
  • Animals
  • Cortical Spreading Depression / drug effects*
  • Cortical Spreading Depression / physiology
  • Cyclic GMP / metabolism*
  • Cyclic GMP / physiology
  • Cyclic Nucleotide Phosphodiesterases, Type 5
  • Electric Stimulation
  • Extracellular Space / drug effects*
  • Extracellular Space / metabolism
  • Male
  • Microdialysis
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Nitric Oxide Synthase / metabolism
  • Phosphodiesterase Inhibitors / pharmacology*
  • Piperazines / pharmacology
  • Purines
  • Purinones / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Sildenafil Citrate
  • Sulfones


  • Phosphodiesterase Inhibitors
  • Piperazines
  • Purines
  • Purinones
  • Sulfones
  • Sildenafil Citrate
  • Nitric Oxide Synthase
  • 3',5'-Cyclic-GMP Phosphodiesterases
  • Cyclic Nucleotide Phosphodiesterases, Type 5
  • Pde5a protein, rat
  • zaprinast
  • Cyclic GMP
  • NG-Nitroarginine Methyl Ester