| Autor: |
Huey KA; Department of Medicine 0623A, Physiology Division, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0623, USA., Szewczak JM, Powell FL |
| Jazyk: |
angličtina |
| Zdroj: |
Respiratory physiology & neurobiology [Respir Physiol Neurobiol] 2003 May 30; Vol. 135 (2-3), pp. 133-44. |
| DOI: |
10.1016/s1569-9048(03)00032-6 |
| Abstrakt: |
Data supporting the hypothesis that dopamine-2 receptors (D(2)-R) contribute to time-dependent changes in the hypoxic ventilatory response (HVR) during acclimatization to hypoxia are briefly reviewed. Previous experiments with transgenic animals (D(2)-R 'knockout' mice) support this hypothesis (J. Appl. Physiol. 89 (2000) 1142). However, those experiments could not determine (1) if D(2)-R in the carotid body, the CNS, or both were involved, or (2) if D(2)-R were necessary during the acclimatization to hypoxia versus some time prior to chronic hypoxia, e.g. during a critical period of development. Additional experiments on C57BL/6J mice support the idea that D(2)-R are critical during the period of exposure to hypoxia for normal ventilatory acclimatization. D(2)-R in carotid body chemoreceptors predominate under control conditions to inhibit normoxic ventilation, but excitatory effects of D(2)-R, presumably in the CNS, predominate after acclimatization to hypoxia. The inhibitory effects of D(2)-R in the carotid body are reset to operate primarily under hypoxic conditions in acclimatized rats, thereby optimizing O(2)-sensitivity. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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