A modified method for the simultaneous determination of regional single-transit brain extraction of diffusion-limited compounds and cerebral blood flow: utilization of non-invasive measurement of transit time.
A dual-label radioisotope method to measure regional cerebral blood flow (CBF) with [14C]butanol and the single-transit brain extraction of [3H]water (Ew) was modified to permit concomittant measurement of the exit time through the cerebrovasculature of a bolus (BET) of 51chromium (51Cr)-labeled ethylenediaminetetraacetic acid (EDTA) in rodents. First, [51Cr]EDTA was injected intravenously via the femoral vein and its transit through cerebrovasculature determined by external gamma counting. The BET measurement was then used to determine the optimum time for animal sacrifice for subsequent measurement of CBF and Ew to minimize both intravascular contamination and washout of butanol and water. This procedure resulted in higher CBF at moderate hypercapnia and slightly lower Ew as a function of arterial CO2 content than previously found using a fixed interval for sacrifice.
D020001:1-Butanol; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D000440:Butanols / Q000378:metabolism; D004492:Edetic Acid / Q000378:metabolism; D008297:Male; D009482:Neurophysiology / Q000379:methods*; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow; D014867:Water / Q000378:metabolism
D000440:Butanols; D014867:Water; D020001:1-Butanol; D004492:Edetic Acid