Insulin coma therapy: Decrease of plasma tryptophan in man

Abstract

A biochemical study was performed in two patients submitted to insulin coma therapy. The injection of insulin resulted in a decrease of free and total tryptophan as well as tyrosine in plasma, while NEFA were not influenced by this treatment. The ratio of tryptophan to tyrosine was enhanced. The administration of glucose after insulin provoked an increase of free and total tryptophan. The results support the hypothesis that in man insulin may favor the uptake of tryptophan by the brain, and enhance the synthesis of cerebral serotonin.

Migraine: A disorder of metabolism?

“…(Dallman et al, 1995). A significantly raised insulin can affect the uptake of Trp and influence the synthesis of 5-HT in the brain [18]. Food intake can alter the level of transmitter that serotoninergic neurons release such that carbohydrates with a higher glycemic index may have a greater serotoninergic effect than carbohydrates with a low glycemic index (Please add reference 206 (i.e.…”

Transport Systems and Enzymes Involved in the Metamorphosis of Tryptophan into Serotonin

“…As a result, after insulin, more Trp will be bound in plasma (12), and some authors find an increase of total plasma Trp (17). But, due to the lower capacity of human plasma proteins to bind Trp, total plasma Trp decreases in human subjects after insulin (3,24). On the other hand, a protein meal which generally contains less Trp than other amino acids, will provoke a decrease in the ratio Trp/LNAA in plasma, and no increase,or only a moderate one, of Trp in the brain (16).…”

Profile: Dr Bourne's identity –credit where credit's due

“…Further, such prolonged use and advocacy of an ineffective treatment by pillars of the psychiatric profession meant that even though insulin coma therapy had largely fallen out of use in Britain and the USA by the 1970s, it was still being practised and researched in some hospitals 7 and may have continued for longer in countries such as China and the Soviet Union. 8 And even more bizarrely, the leading advocates of the treatment suffered no repercussions as far as their own careers were concerned.…”