Studies on the plasma cyclic nucleotide levels in patients with acute cerebro-vascular disorders

Abstract

Plasma cyclic adenosine 3', 5'-monophosphate (cAMP) and cyclic guanosine 3', 5'-monophosphate (cGMP) levels were measured by the competitive radioimmunoassay method in 13 patients with cerebral infarction and 8 patients with intracerebral hemorrhage soon after onset. Control studies were performed on out-patients more than 3 months after cerebral stroke and 225 normal volunteers. The results are as follows : 1) The mean plasma cAMP and cGMP levels of normal volunteers were 20.7±3.8 and 4.7±1.6 pmol/ml respectively with the cAMP/cGMP ratio of 4.8±1.7. 2) All the 11 patients in acute phase of cerebral infarction, who ultimately survived, showed almost normal levels of plasma cAMP and increased levels of plasma cGMP with significant difference from controls (p<0.001) on the first day of stroke, showing cAMP/cGMP ratio definitely lower than controls. Two patients, died in the course of acute cerebral infarction showed moderately increased plasma levels of cAMP and slightly increased plasma levels of cGMP with normal cAMP/cGMP ratio. 3) Five patients, died of intracerebral hemorrhage showed markedly increased plasma levels of cAMP, with scarcely increased plasma levels of cGMP, on the first day of stroke, with higher cAMP/cGMP ratio than that in patients in acute stage of cerebral infarction and controls. 4) The daily plasma levels of cAMP and cGMP were determined at least during the first week after onset in acute cerebral infarction. In survival cases, plasma cGMP kept in higher levels than controls, while plasma cAMP remained almost within normal range. Normalization of plasma cGMP level was found earlier in cases with more marked and rapid improvement than in cases with delayed improvement. 5) The inverse correlation was demonstrated between plasma cGMP levels and the Frithz's prognostic scores in 22 cases with acute cerebral infarction within 72 hours after onset with coefficient (r=0.53, p<0.02). From these findings, it was suggested that determination of plasma cGMP level in acute stage of cerebral infarction may be useful for the evaluation of its prognosis.