DEHYDRATION AND FOOD-DEPRIVATION EXACERBATE MOUSE CEREBRAL MICROVASCULAR RESPONSES TO LOCAL HYPERTHERMIA

1. Effects of 1-day deprivation from water, food or both on responses of mice pial microvessels to local cerebral hyperthermia were compared to fed mice and with access to water. 2. A set of protocol for all gr oups was followed, which involved microsurgery and utilized intravital videomicroscopy. Core body temperature was kept at 37 degrees C and h yperthermic exposure was applied locally by heating the artificial cer ebrospinal Fluid irrigating the brain surface, at 45 degrees C for 25 min. 3. Monitored responses included intravascular thrombo-embolic eve nts and changes in microvascular diameter. Dehydration and food depriv ation shortened the time for appearance of passing emboli and lowered the thermal threshold at which thrombo-embolic processes occur. 4. Art eriolar constriction was observed in all groups, coupled with full occ lusion. 5. Data of this study revealed that dehydration and food depri vation exacerbate pial microcirculatory responses to local hyperthermi a.