A role for guanidino compounds in the brain

Area of Science:

• Neuroscience
• Biochemistry
• Toxicology

Background:

• Guanidino compounds are prevalent in the mammalian brain.
• Several guanidino compounds, excluding arginine and guanidine, are identified as potent convulsants.
• Changes in brain levels of specific guanidino compounds correlate with induced convulsions.

Purpose of the Study:

• To investigate the convulsant properties of various guanidino compounds.
• To explore the role of guanidino compounds in seizure induction and brain function.
• To understand the involvement of free radicals and energy metabolism in guanidino compound-induced convulsions.

Main Methods:

• Intracisternal injection of guanidino compounds in animal models (rat, rabbit, cat).
• Monitoring brain levels of guanidino compounds during induced convulsions (pentylentetrazol, amygdala kindling, iron-induced epileptogenesis).
• Assessing the effects of guanidino compounds on neuronal function and cell death.

Main Results:

• Intracisternal administration of most guanidino compounds induced seizures and convulsions.
• Specific guanidino compounds like alpha-guanidinoglutaric acid generated reactive oxygen species and nitric oxide, leading to glial cell death.
• Aminoguanidine demonstrated free radical scavenging properties.
• Creatine metabolism's role in energy formation and potential apoptosis inhibition was noted.

Conclusions:

• Guanidino compounds play a significant role in brain function, particularly in seizure generation and potentially in neurological pathogenesis.
• Free radical generation and energy metabolism mediated by guanidino compounds are critical factors in the brain.
• Further research into guanidino compounds could offer insights into epilepsy and neuroprotective strategies.