GMP and prolactin
Research type
Research Study
Full title
Effect of a milk-derived protein (GMP) on prolactin: a controlled study
IRAS ID
129563
Contact name
Philip Cowen
Contact email
Sponsor organisation
University of Oxford
Research summary
Dopamine is a chemical messenger found in the brain that is thought to be overactive in certain serious psychiatric disorders such as schizophrenia. Dopamine receptor blocking drugs are widely used to treat conditions such as schizophrenia but have unpleasant side effects. Dopamine is made in the brain from a natural amino acid called tyrosine and we have previously found that it is possible to influence dopamine by altering the amount of tyrosine available to the brain using a special amino acid mixture. Though this mixture was effective in lowering dopamine it was not pleasant to take because of its unpleasant taste, and it is also difficult to make.
In this study we would like to see if we can obtain a similar effect using a protein derived from cows’ milk called Glycomacroprotein (GMP), which happens to be virtually free of tyrosine. GMP is often used in food manufacture and it is easy to make palatable. We will measure the effect of GMP on dopamine activity using two kinds of test. The first is by taking a series of blood samples in which we can measure levels of a natural hormone called prolactin. When dopamine in the brain falls, prolactin levels in the blood rise. The other test involves memory. Lowered dopamine levels change performance on a particular kind of memory task which can be easily measured on a computer.
The study will be carried out in 24 healthy volunteers who will take a single dose either of GMP or a control protein, called alpha-lactalbumin. Alpha lactalbumin is also derived from milk but contains a normal amount of tyrosine
REC name
East of England - Cambridgeshire and Hertfordshire Research Ethics Committee
REC reference
13/EE/0136
Date of REC Opinion
5 Jun 2013
REC opinion
Further Information Favourable Opinion