Intraperitoneal administration and other modifications of the 2-deoxy-D-glucose technique

Experiments were conducted to determine the optimal conditions necessary for implementing modifications of the 2-deoxyglucose (2-DDG) technique. Substitution of tritium-labeled 2-DDG with subsequent microdissection of selected brain regions and liquid scintillation counting produced results that were highly correlated with both [14C]radioautograms and glucose utilization values as obtained by Sokoloff et al. The route of administration of isotope was also varied. Whole brain uptake at maximal levels of incorporation was the same for both intravenously and intraperitoneally injected animals. Radioautograms from i.p. and i.v. injected animals were indistinguishable. Densitometric analyses of the i.p. radioautograms were highly correlated with glucose utilization values. Thus, relative indices of functional activity may be obtained when experimental circumstances preclude arteriovenous cannulations and restraint. The use of naive, unrestrained animals, therefore, makes the 2-DDG technique applicable to a broader range of studies.