Related Experiment Videos
Evidence for nitric oxide-generator cells in the brain
L Ma1
1Department of Physiological Chemistry, Faculty of Dentistry, Tokyo Medical and Dental University.
The Bulletin of Tokyo Medical and Dental University
|September 1, 1993
Summary
Nitric oxide (NO), a neuronal messenger, is generated by brain neurons, astrocytes, and microvessel endothelial cells. NO synthase (NOS) activity was measured to map NO production in the central nervous system.
Area of Science:
- Neuroscience
- Cell Biology
Background:
- Nitric oxide (NO) is recognized as a key neuronal messenger molecule in the central nervous system (CNS).
- Identifying NO-generating and NO-targeting cells is crucial for understanding NO's function in the brain.
Purpose of the Study:
- To investigate the distribution and cellular sources of nitric oxide synthase (NOS) in the brain.
- To characterize NO production by neuronal cells, astrocytes, and brain microvessel endothelial cells.
Main Methods:
- Measured NOS activity via citrulline formation, an indicator of NO synthesis from L-arginine.
- Assessed intracellular cyclic guanosine monophosphate (cGMP) levels in astrocytes as a marker of NO production.
- Examined NOS activity in neuronal cultures, astrocyte cultures, and brain microvessel endothelial cells from rats and pigs.
Main Results:
- High NOS activity was detected in the cerebellum, olfactory bulb, and cerebrum of adult rats.
- Both fetal rat neurons and astrocytes exhibited significant NOS activity.
- NOS activity was also found in microvessel endothelial cells of the cerebrum in both adult and fetal pigs.
- Astrocytes showed NOS activity and responded to NO, indicated by changes in cGMP levels.
Conclusions:
- Neuronal cells are likely the primary sites of NO generation in the brain, with constitutive NOS.
- Astrocytes also produce NO via constitutive NOS, contributing to NO signaling.
- Brain microvessel endothelial cells are another source of NO, influencing astrocyte cGMP levels and potentially brain function.