The rostral ventrolateral medulla (RVLM) regulates vasomotor activity via sympathoexcitation and sympathoinhibition to maintain blood pressure. Nitric oxide synthesized by nitric oxide synthase (NOS) I and NOS II within RVLM is responsible for sympathoexcitation and sympathoinhibition respectively. In our previously study, under physiological condition RVLM neurons contain both NOS I and NOS II protein, and NOS III protein is expressed mainly on blood vessels.
Under Mevinphos (Mev) intoxication, our previously study demonstrates that the expression of RVLM NOS I and II mRNA or protein are both increased under Mev intoxication phase I, and NOSII mRNA or protein are further increased under Mev intoxication phase II. On the other hand, in rat central nervous system, about 65% of total cells are glial cells, including astrocytes, microglia and oligodendrocytes. However, the expressions of NOS isoforms in RVLM glial cells still need to be determined.
We used double immunofluorescence staining and confocal microscopy to investigate the distributions of NOS isoforms protein in RVLM neurons and glial cells under physiological condition and under pathological condition using Mev intoxication as our model. We further compared the distributions of NOS isoforms in RVLM neurons and glial cells under physiological or pathological conditions.
The confocal images indicate that NOS I protein reactivity co-localized with neurons and microglia in the RVLM. NOS II protein reactivity co-localized with neurons, astrocytes and microglia. NOS III protein reactivity co-localized with blood vessels and microglia. The distributions of NOS isoforms protein reactivity in RVLM neurons and glial cells under Mev intoxication are the same as under physiological condition. Furthermore, the expressions of NOS I protein within neurons or microglia and NOS II in neurons, astrocytes or microglia are progressively increased under Mev intoxication. On the other hand, the expression of NOS III within microglia under Mev intoxication was similar to physiological condition. The population of NOS I-positive neurons or microglia, and NOS II-positive neurons, astrocytes or microglia increased under Mev intoxication. However the population of NOS III-positive microglia decreased under Mev intoxication.
These results indicate that within RVLM, the distributions of NOS I are in neurons and microglia; NOS II are in neurons, astrocytes and microglia; NOS III are in blood vessels and microglia. We suggest that under Mev intoxication, the source of up-regulated NOS I protein includes neurons and microglia; and the up-regulated NOS II protein comes from neurons, astrocytes and microglia.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0815105-173007 |
| Date | 15 August 2005 |
| Creators | Tsai, Po-chuan |
| Contributors | Chan, JYH, Chan, SHH, Chang, AYW |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0815105-173007 |
| Rights | campus_withheld, Copyright information available at source archive |
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