Purpose: Exercise-induced hypoxemia in highly trained athletes is associate
d with an increase in histamine release during exercise. The cells most imp
licated in blood histamine release are basophils. The aim of this study was
to determine whether high-level endurance training induces modifications i
n histamine releasability from human basophils. Methods: Seven young highly
trained athletes (YA) [aged 26.1 +/- 1.3 yr (mean +/- SEM)] and seven mast
er athletes (MA) (64.4 +/- 4.1 yr), all known to develop exercise-induced h
ypoxemia, were respectively compared with seven young untrained men (YC) (2
3.0 +/- 1.5 yr) and seven older untrained men (OC) (61.6 +/- 1.3 yr). Durin
g an incremental exhaustive exercise, blood samples for measurement of anti
-IgE-induced histamine release from leukocytes were drawn at real, (V)over
dot O-2max, and recovery. Results: Basophils from "leukocyte-rich" supernat
ant in YA and MA showed significantly higher histamine release induced by a
nti-IgE (1 mu g.mL(-1)) than, respectively, YC (P < 0.01) and OC (P < 0.05)
at rest, (V)over dot O-2max (P < 0.01), and recovery (P < 0.01). Basophils
in YA and MA also showed a histamine release induced by anti-IgE that was
higher at (V)over dot O-2max than at rest (respectively, P < 0.01 and P < 0
.05), but this change was not found in the control groups. Conclusion: In c
onclusion, the basophils in highly trained endurance athletes, both young a
nd older, showed higher anti-IgE-induced histamine release than those of un
trained men. This effect of high-level training seemed to be potentiated by
exercise.