EFFECTS OF AN INHIBITOR OF ADENOSINE-DEAMINASE, DEOXYCOFORMYCIN, AND OF NUCLEOSIDE TRANSPORT, PROPENTOFYLLINE, ON POSTISCHEMIC RECOVERY OF ADENINE-NUCLEOTIDES IN RAT-BRAIN

The effects of an adenosine deaminase inhibitor (deoxycoformycin, 500 mu g/kg) and of an inhibitor of nucleoside transport (propentofylline, 10 mg/kg) on adenosine and adenine nucleotide levels in the ischemic rat brain were investigated. The brains of the rats were microwaved be fore, at the end of a 20 min period of cerebral ischemia (4 vessel occ lusion + hypotension), or after 5, 10, 45, and 90 min of reperfusion. Deoxycoformycin increased brain adenosine levels during both ischemia and the initial phases of reperfusion. AMP levels were elevated during ischemia and after 5 min of reperfusion. ATP levels were elevated abo ve those in the non-treated animals after 10 and 45 min of reperfusion . ADP levels were elevated above the non-drug controls at 90 min. Thes e increases in ATP, ADP and AMP resulted in significant increases in t otal adenylates during ischemia, and after 10 min and 90 min of reperf usion. Propentofylline administration resulted in enhanced AMP levels during ischemia but did not alter adenosine or adenine nucleotide leve ls during reperfusion in comparison with non-treated controls.