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Dual effects of nitric oxide on cat carotid body chemoreception.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Iturriaga, Rodrigo Villanueva, Sandra Mosqueira, MatÃas |
| Copyright Year | 2000 |
| Abstract | We studied the effects of nitric oxide (NO) released by NO donors on cat carotid body (CB) chemosensory activity during normoxia and hypoxia. CBs excised from pentobarbital sodium-anaesthetized cats were perfused with Tyrode at 38 degrees C and pH 7.40. The frequency of chemosensory discharges (f(x)) was recorded from the carotid sinus nerve, and changes of NO concentration were measured by a chronoamperometric technique, with NO-selective carbon-fiber microelectrodes inserted in the CB. During steady chemosensory excitation induced by hypoxia, bolus injections of NO (DeltaNO = 0. 5-12 microM), released by S-nitroso-N-acetylpenicillamine (SNAP) and 6-(2-hydroxy-1-methyl-nitrosohydrazino)-N-methyl-1-hexanamine++ + (NOC-9), transiently reduced f(x) in a dose-dependent manner. However, during normoxia, the same concentration of NO (DeltaNO = 0. 5-13 microM) released by the NO donors increased f(x) in a dose-dependent manner. The present results show a dual effect of NO on CB chemoreception that is dependent on the PO(2) levels. During hypoxia, NO is predominantly an inhibitor of chemoreception, whereas, in normoxia, NO increased f(x). The mechanisms by which NO produces chemosensory excitation during normoxia remain to be determined. |
| Starting Page | 213 |
| Ending Page | 218 |
| Page Count | 6 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://jap.physiology.org/content/jap/89/3/1005.full.pdf |
| PubMed reference number | 10956344v1 |
| Volume Number | 89 |
| Issue Number | 3 |
| Journal | Journal of applied physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Body Fluid Discharge Carotid Body Clinical act of insertion Dual Excitation Hypoxia NOC 9 Nasal sinus Nitric Oxide Pentobarbital Sodium S-Nitroso-N-Acetylpenicillamine Structure of carotid sinus Tissue fiber |
| Content Type | Text |
| Resource Type | Article |
