Brain Monoamines in Cerebral Infarction and Coma

Abstract

Dopamine (DA), serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) and tryptophan (Trp) were assayed spectrofluorometrically in various brain regions of eight human patients who died after acute and old cerebral infarction, in 17 cases of acute metabolic (hepatic, uremic and diabetic) coma, and in three patients with liver cirrhosis without coma. The results were as follows: (1) In both recent and older cerebral infarction a total depletion of DA and 5-HT was associated with slight reduction of DA and 5-HT levels in remote non-ischemic areas and various nuclei of both the injured and contralateral hemispheres. 5-HIAA was significantly reduced in acute ischemic necrosis, while the perifocal edema zone showed accumulation of both 5-HT and 5-HIAA. The degradation zone surrounding old infarcts showed a mild decrease of both 5-HT and 5-HIAA, indicating normalization of 5-HT metabolism after decrease of the complicating edema. (2) In metabolic coma brain DA showed a mild general decrease, while brain Trp was significantly increased in hepatic coma. 5-HT and 5-HIAA were generally increased in all types of coma, most significantly in the brainstem tegmentum and in parts of the limbic system. (3) In liver cirrhosis without coma, brain 5-HT was within normal range, while Trp and 5-HIAA were significantly elevated in the brainstem, their increase being less severe than in hepatic coma.