Uptake and efflux of serotonin from platelets of autistic and nonautistic children.

This study examined, in vitro, the uptake and efflux of serotonin by platelets from autistic children, nonautistic hospitalized comparison cases, and normal children. The autistic patients were carefully selected according to previously established diagnostic criteria. The hospitalized comparison children were utilized to assess possible environmental and dietary influences upon the results. Uptake methods were similar to those used by previous investigators. Two efflux procedures were utilized to explore the possibility that methodological factors accounted for previously reported differences between autistic and comparison groups. The results failed to indicate statistically significant differences in uptake or efflux between the autistic and the hospitalized comparison groups or the normals. Methodologic considerations which could possibly account for the failure to confirm previous findings are discussed in detail.