Polyamines inhibit nitric oxide synthase in rat cerebellum

Jingru Hu, Mahmoud I. Mahmoud, Esam E. El-Fakahany

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


The polyamines spermine, spermidine and putrescine share some basic structural features with l-arginine, the substrate of nitric oxide (NO) synthase. The effects of the polyamines on neuronal NO synthase activity were studied in cytosolic preparations of rat cerebellum and cultured cerebellar granule neurons. Spermine, spermidine and putrescine all inhibited the conversion of [3H]l-arginine to [3H]l-citrulline by NO synthase, with the following rank order of potency: spermine > spermidine > putrescine. These inhibitory effects of the polyamines on [3H]l-citrulline formation were also observed in intact cultured cerebellar granule neurons upon stimulation of N-methyl-d-aspartate (NMDA) receptors. Evidence was obtained, however, that endogenous polyamines are not involved in regulation of NMDA-stimulated NO synthase activity. Thus, the observed inhibitory effects of exogenous polyamines might not reflect a physiological role in modulating NO generation in neurons.

Original languageEnglish (US)
Pages (from-to)41-45
Number of pages5
JournalNeuroscience Letters
Issue number1-2
StatePublished - Jul 4 1994

Bibliographical note

Funding Information:
This work was supported in part by NIH Grant NS-25743 and by a contract from the US Army Research Office.


  • N-methyl-d-aspartate
  • Nitric oxide synthase
  • Ornithine decarboxylase
  • Polyamine
  • Putrescine
  • Spermidine
  • Spermine


Dive into the research topics of 'Polyamines inhibit nitric oxide synthase in rat cerebellum'. Together they form a unique fingerprint.

Cite this