Related Experiment Videos
Pipecolic acid induces apoptosis in neuronal cells.
Shinji Matsumoto1, Satoshi Yamamoto, Katsunari Sai
1Department of Physiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan.
Brain Research
|July 18, 2003
Summary
Pipecolic acid, a lysine metabolite, may cause hepatic encephalopathy by inducing neuronal cell death, including apoptosis. This study found it did not depress neurotransmission but significantly reduced cell viability.
Area of Science:
- Neuroscience
- Biochemistry
- Cell Biology
Background:
- Pipecolic acid, a lysine metabolite, is implicated in hepatic encephalopathy.
- The precise mechanism underlying pipecolic acid's role in hepatic encephalopathy remains unclear.
Purpose of the Study:
- To investigate the neurotoxic effects of pipecolic acid.
- To elucidate the mechanism by which pipecolic acid may contribute to hepatic encephalopathy.
Main Methods:
- Electrophysiological recordings in rat hippocampal slices to assess synaptic responses.
- Whole-cell voltage-clamp studies on cultured neurons and Neuro-2A cells to examine ion channel activity.
- Cell viability assays (MTT, propidium iodide, Hoechst 33,342 staining) to evaluate neurotoxicity and apoptosis.
Main Results:
- Pipecolic acid (D-, L-, DL forms) did not inhibit excitatory postsynaptic responses in hippocampal slices.
- DL-pipecolic acid potentiated voltage-sensitive Ca(2+) channel currents in neurons but did not affect Na(+) or K(+) currents.
- Long-term exposure to pipecolic acid induced dose-dependent cell death and apoptosis in Neuro-2A cells, with DL-pipecolic acid being most potent.
Conclusions:
- Pipecolic acid may induce hepatic encephalopathy through neuronal cell death, potentially via apoptosis.
- Neurotransmission depression is unlikely to be the primary mechanism of pipecolic acid's neurotoxicity in hepatic encephalopathy.