The effect of anaesthetics on the uptake of brain-imaging agents in rats.

Anaesthetics are shown to affect the brain uptake of two pH-shift brain imaging agents, di-B-(morpholinoethyl)-selenide and N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine significantly. This is probably due to changing regional cerebral blood flow. The present study reaffirms previous observations that small disturbances such as stress and type of anaesthesia will significantly alter the regional cerebral blood flow and, as a consequence, brain uptake in rats. This is an important factor to consider when measuring or comparing brain uptake data.