Simultaneous measurement of local glucose utilization and blood flow in the rat brain: an autoradiographic method using two tracers labeled with carbon-14.

A simplified technique that uses two radionuclide tracers has been devised to measure local cerebral glucose utilization (ICGU) and local cerebral blood flow (ICBF) in the same rat. The method employs [14C]-2-deoxyglucose and [14C]iodoantipyrine to produce an autoradiogram before and another after extraction into chloroform of the [14C]iodoantipyrine from the brain sections. The chloroform-extracted autoradiogram yields ICGU, and the difference in tissue carbon-14 concentration between the two autoradiograms permits calculation of ICBF. The double-isotope technique provides values of ICGU and ICBF that are statistically indistinguishable from those derived from conventional single-isotope methods.