RESUMO
A method for the investigation of cerebral blood flow changes under the influence of vasoactive drugs has been suggested. The method is based on continuous infrared radiation and registration of the reflection from the local brain region through the cerebral cranium. The experiments were conducted on anesthetized cats. The dependence of Pa CO2 on the recorded parameters is shown. The changes in the cerebral blood flow (in conventional units) determined by the alterations of the infrared radiation reflection are shown upon the injection of 1.2 microgram/kg, 2.5 micrograms/kg and 5 micrograms/kg of noradrenaline.
Assuntos
Fármacos Cardiovasculares/farmacologia , Circulação Cerebrovascular/efeitos dos fármacos , Raios Infravermelhos , Animais , Pressão Sanguínea/efeitos dos fármacos , Dióxido de Carbono/sangue , Gatos , Circulação Cerebrovascular/efeitos da radiação , Métodos , Oxigênio/sangue , Pressão Parcial , Espalhamento de RadiaçãoRESUMO
A noninvasive method of quantitative assessment of cerebral blood flow based on heat clearance from brain tissues is described. The rate of heat clearance depends essentially on the blood flow. The employment of microwave techniques permits to warm the investigated brain zone and to record the temperature decrease extracranially. As a thermometer, a microwave radiometer was used. The experiments were carried out on cats. The method was tested by current vasoactive drugs.