[Blood serotonin and histamine in sheep with endemic scrapie: initial results].

The whole blood histamine levels of sheep without clinical scrapie but living in infected farms, control, and scrapie infected sheep are not significantly different. By contrast whole blood serotonin is decreased both in sheep living in infected farms and in scrapie-infected sheep as compared to controls. Thrombopenia may account for the hyposerotoninemia of sheep living in infected farms except those genetically linked to scrapie-infected sheep for which, as for scrapie-infected sheep, platelet serotonin appears also to be diminished. Whole blood serotonin determination might therefore be useful to detect sheep living in infected farms (these sheep probably play an important role in scrapie infection) and perhaps also humans with high susceptibility to Creutzfeldt-Jakob disease.