I first met Peter a couple of years ago at an Autism Research Institute Think Tank. At the Think Tank Peter impressed everybody with his knowledge, specially about biochemical pathways. He was my lunch buddy for that couple of days and ever since we have kept in touch. I invited him to write a contribution to my blog and he obliged. You can read about his ideas regarding fever and the clinical manifestations of ASD in a previous blog: http://bit.ly/10NyJFk. Peter also wrote a related blog about an oral using citrulline for ASD: http://bit.ly/1PY6Nm4

Peter just finished writing a blog regarding his experience with citrulline in his web site http://www.autismstudies.net and asked me to see whether I could publish the conclusions in my own blog.

Here are my [Peter’s] conclusions after five months of citrulline:

Considerable evidence argues the brain hemispheres of autistic children are isolated and atypically asymmetric in anatomy, function, neurochemistry, and blood flow. Low brain blood flow in hyperexcitable children is especially anomalous – suggesting failure of neurovascular coupling from lack of nitric oxide, the primary vasodilator, or its substrate arginine. Is too much arginine taken up by the liver to detoxify ammonia? One test is oral citrulline, which bypasses the liver and forms arginine in the kidneys, increasing systemic arginine. Replacing 2g/day of oral arginine with 2–4g/day oral citrulline (+ 2–4g/day taurine) evoked spontaneous speech, calmed anxiety, and enhanced focus and planning – left hemisphere attributes. Evidence that glutathione sustains release of nitric oxide prompted addition of undenatured whey protein for glutathione precursors. Evidence that glutathione also matures myelin argues glutathione depletion is a key mechanism in autism – keeping myelin immature, brain hemispheres isolated, and brain blood flow low.

Was my trial of citrulline too subjective? My best evidence is spontaneous speech. I rarely notice right away I’m reading or thinking aloud; in other words, I hear myself speaking, I didn’t intend to. Who is speaking?