Increased levels of free serotonin in plasma of symptomatic asthmatic patients.
BACKGROUND
Previous research has shown that symptomatic asthmatic patients have increased levels of norepinephrine, epinephrine, dopamine, free serotonin, and cortisol in plasma when compared with asymptomatic patients.


OBJECTIVE
We investigated the relationship between plasma levels of catecholamines, free serotonin, and cortisol and clinical status and pulmonary function in symptomatic and asymptomatic patients with asthma.


METHODS
We compared clinical severity, spirometry, and neuroendocrine factors at weeks 0, 1, 2, 3, and 4 in 57 symptomatic (forced expiratory volume in one second [FEV1] < 70%) and 72 asymptomatic (FEV1 > 80%) asthmatic patients. We used multiple analyses of variance (repeated measures) to interpret the data. In addition, we used the Pearson Product Moment Test to investigate correlations among the different variables.


RESULTS
The clinical severity rating and levels of free serotonin, norepinephrine, epinephrine, dopamine, and cortisol were significantly higher in symptomatic asthmatic patients than those in asymptomatic patients (P < .001, in all cases). FEV1 was significantly lower in symptomatic patients than in asymptomatic patients. In symptomatic patients, the level of free serotonin correlated positively with the clinical severity rating (r = .564, P < .01) and negatively with FEV1 (r = -.959, P < .001). In addition, the clinical severity rating showed a negative correlation with FEV1 (r = -.359, P < .01). No significant correlations were found in asymptomatic patients.


CONCLUSIONS
Our finding that free serotonin was the only neuroendocrine factor closely associated with clinical severity and pulmonary function suggests that this factor plays an important role in the pathophysiology of acute asthma.
Lechin
F
F
Section of Psychopharmacology, Institute of Experimental Medicine, Faculty of Medicine, Central University of Venezuela, Caracas, Venezuela.
van der Dijs
B
B
Orozco
B
B
Lechin
M
M
Lechin
A E
AE
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000097:blood*; D002648:Child; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D010974:Platelet Aggregation; D012701:Serotonin / Q000097:blood*
D012701:Serotonin