M. Jeziorska et al., MAST-CELL AND EOSINOPHIL DISTRIBUTION AND ACTIVATION IN HUMAN ENDOMETRIUM THROUGHOUT THE MENSTRUAL-CYCLE, Biology of reproduction, 53(2), 1995, pp. 312-320
Tryptase and chymase immunolocalization techniques have been used to e
xamine the distribution, activation, and tryptase/chymase phenotype of
mast cells (MCs) in 107 endometrial specimens that represented every
day of the hu man menstrual cycle. MCs were identified in the endometr
ium in all stages of the menstrual cycle; similar MC numbers were obse
rved for the functionalis, basalis, and muscularis. Extensive MC activ
ation/degranulation, as judged by extracellular tryptase, was a common
feature of the functionalis in specimens sampled just prior to and du
ring menstruation. MC activation was also prominent in the functionali
s at times coincident with recognized stromal edema. MCs of the functi
onalis did not contain chymase; all stained for tryptase acid represen
t the MC(T) phenotype. By contrast, the basalis and muscularis showed
a proportion of MCs containing both tryptase and chymase, MC(TC). One
important function for extracellular MC tryptase and chymase is their
ability to activate precursor forms of the matrix metalloproteinases,
enzymes recognized as instrumental in stromal degradation. Quantitativ
e analysis of MC numbers, expressed relative to stromal cell numbers/m
m(2), indicated no major changes during the menstrual cycle, although
changes in MC morphology, granule content, and activation/degranulatio
n were recognized for specific stages. Eosinophils, detected with mono
clonal antibodies EG1 and EG2, were absent from extravascular sites be
tween Days 5 and 26 but showed local accumulations just prior to and d
uring menstruation, Since MCs and eosinophils between them contain a v
ariety of potent mediators, it seems likely that both cell types assum
e important functional roles in relation to tissue and vascular remode
ling associated with endometrial physiology.