Plasma precursors of brain catecholaminergic and serotonergic neurotransmitters in rehabilitation patients with ischemic stroke.
OBJECTIVE
To determine levels of plasma amino acid tyrosine and tryptophan, precursors of brain catecholamine and serotonin neurotransmitters, respectively, in rehabilitative patients with ischemic stroke.


METHODS
Controlled, pre-post analysis, consecutive sample.


METHODS
Rehabilitation center.


METHODS
Twenty men with ischemic stroke (age, 68+/-11.3y) consecutively admitted into rehabilitation 15+/-10 days (range, 7-28d) after an acute cerebrovascular insult; 15 healthy sedentary subjects (controls 1); and 13 healthy hypoactive individuals who had recently had knee arthroplasty (controls 2). Both control groups were matched to stroke subjects for age, gender, and body weight.


METHODS
At 8:00 am, after overnight fasting, venous blood samples were drawn from patients to determine plasma tyrosine and tryptophan levels. A nutritional evaluation, including nitrogen balance, was made. The same procedures were repeated after 45 days of rehabilitation. Amino acid data were compared with those obtained from the controls.


METHODS
Plasma concentrations of amino acids.


RESULTS
Patients with ischemic stroke, on admission, had lower plasma tyrosine concentration than did both controls 1 (P<.0005) and controls 2 (P<.001), but a similar tryptophan level. The plasma content of tyrosine was similar between the 2 control groups. After 45 days of rehabilitation, the stroke patients' tyrosine and tryptophan levels remained virtually unchanged, as did nutritional parameters. Nutritional intakes were adequate to meet body needs but insufficient to correct plasma tyrosine.


CONCLUSIONS
Patients experiencing a recent stroke may have low plasma tyrosine levels and, therefore, reduced brain catecholamine formation. It is possible that an imbalance of brain neurotransmitters may occur.
Aquilani
Roberto
R
Servizio di Fisiopatologia Metabolico-Nutrizionale e Nutrizione Clinica, Fondazione S Maugeri, Istituto Scientifico di Montescano, Montescano, Pavia, Italia.
Verri
Manuela
M
Iadarola
Paolo
P
Arcidiaco
Patrizia
P
Boschi
Federica
F
Dossena
Maurizia
M
Sessarego
Paolo
P
Scocchi
Marco
M
Arrigoni
Nadia
N
Pastoris
Ornella
O
D000368:Aged; D002545:Brain Ischemia / Q000097:blood* / Q000534:rehabilitation; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D009752:Nutritional Status; D020521:Stroke / Q000097:blood*; D000071939:Stroke Rehabilitation; D014364:Tryptophan / Q000097:blood*; D014443:Tyrosine / Q000097:blood*
D014443:Tyrosine; D014364:Tryptophan