RESUMO
Cochlear blood flow (CoBF) and cerebral blood flow (CBF) were measured using laser Doppler flowmetry and the microsphere method during CO2 and O2 gas mixture inhalation in rabbits. Both methods revealed that CBF was increased by CO2 inhalation. CoBF measured by laser Doppler measurement decreased during CO2 inhalation while that measured by the microsphere method showed a slight increase, but lateral wall blood flow in the cochlea measured by the microsphere method showed no significant change. Our results obtained with laser Doppler flowmetry were not inconsistent with those reported in humans. It is considered that the rabbit, in which thick bone surrounds the cochlea, is a good model for the experimental evaluation of the laser Doppler technique used in the clinical measurement of CoBF.
Assuntos
Circulação Cerebrovascular , Cóclea/irrigação sanguínea , Hipercapnia/fisiopatologia , Administração por Inalação , Animais , Pressão Sanguínea , Volume Sanguíneo , Dióxido de Carbono/administração & dosagem , Dióxido de Carbono/sangue , Córtex Cerebral/irrigação sanguínea , Ducto Coclear/irrigação sanguínea , Modelos Animais de Doenças , Fluxometria por Laser-Doppler , Microesferas , Oxigênio/administração & dosagem , Oxigênio/sangue , Coelhos , Fluxo Sanguíneo Regional , Rampa do Tímpano/irrigação sanguínea , Lâmina Espiral/irrigação sanguínea , Estria Vascular/fisiologiaRESUMO
We investigated blood flow to the facial nerve, cerebral cortex, brain stem, and dura mater in 16 white rabbits using a nonradioactive microsphere technique at various levels of arterial carbon dioxide tension. The blood flow to the facial nerve in the 32 temporal bones was 59.1 +/- 32.9 microliters/g/min. Unlike cerebral blood flow, blood flow to the facial nerve and dura mater did not show any marked increase upon carbon dioxide inhalation.
