[Cerebral metabolism and permeability of the hemato-encephalic barrier in an experimental model for brain radiotherapy].
Whole brain irradiation (WBR) can produce acute and chronic neurological adverse effects, which are usually divided into acute, early delayed and late delayed reactions according to the time of onset. To assess the impact of WBR on brain functional parameters during the early-delayed phase, we employed the [14C]-2-deoxyglucose (2-DG) and the [14C]-alfa-aminoisobutyric (AIB) acid quantitative autoradiographic techniques to study local cerebral glucose utilization and blood-brain barrier permeability, respectively. Sprague-Dowley albino rats were exposed to conventional fractionation (200 Gy/day 5 days a week) for a total dose of 4000 Gy. Experiments were made 3 weeks after completion of the radiation exposure. In comparison with control and sham-irradiated animals, cerebral metabolic activity was diffusely decreased following irradiation. As a rule, brain areas with the highest basal metabolic rates showed the highest percentage drop in glucose utilization. Changes in blood-brain barrier function, as assessed by an increased transcapillary transport of AIB, were also demonstrated in specific brain regions. This study illustrates how moderate doses of WBR induce well-defined changes in brain metabolism and BBB function, which are possibly involved in the pathogenesis of the early-delayed radiation-induced cerebral dysfunction in humans.
Cicciarello
R
R
Istituto di Clinica Oncologica e Clinica Neurochirurgica, Università, Messina.
Russi
E
E
Albiero
F
F
Mesiti
M
M
Torre
E
E
D'Aquino
A
A
Raffaele
L
L
Bertolani
S
S
D'Avella
D
D
D000621:Aminoisobutyric Acids / Q000378:metabolism; D000818:Animals; D001812:Blood-Brain Barrier / Q000528:radiation effects*; D001921:Brain / Q000378:metabolism* / Q000528:radiation effects; D002199:Capillary Permeability / Q000528:radiation effects*; D016371:Cranial Irradiation; D003847:Deoxyglucose / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D000621:Aminoisobutyric Acids; D003847:Deoxyglucose
Metabolismo cerebrale e permeabilità della barriera ematoencefalica in un modello sperimentale di trattamento radioterapico cerebrale.