Eosinophil degranulation during pregnancy and after delivery by cesarean section.
BACKGROUND
The physiological roles of eosinophils that accumulate in the uterus during pregnancy and of uterus-dwelling mast cells remain unknown. In the present study, we investigated the degranulation of eosinophils and mast cells within the normal course of pregnancy and after delivery by measuring the urinary concentrations of eosinophil-derived neurotoxin (EDN) and N-methylhistamine.


METHODS
Spot urine samples from 65 pregnant women and 15 nonpregnant, age-matched women were examined. Urinary EDN and N-methylhistamine concentrations were measured by radioimmunoassay and standardized with urinary creatinine concentration.


RESULTS
A significant increase in the urinary EDN concentration was observed until the second trimester in the normal pregnancies. The elevated urinary EDN levels decreased after the onset of labor in the third trimester and normalized within 1 month after normal vaginal delivery. In women who underwent a cesarean section, the urinary EDN concentration was significantly higher for up to 1 month after delivery, compared to that in women who underwent a vaginal delivery. In contrast, the urinary N-methylhistamine concentration did not change until the second trimester and was significantly decreased during the third trimester. No significant correlation between the peripheral blood eosinophil count and the urinary EDN concentration was observed in these subjects.


CONCLUSIONS
Eosinophils appear to play a role in the progression of pregnancy and recovery after a cesarean section through the degranulation of eosinophils. In addition, mast cell degranulation does not appear to be related to the contraction of uterine smooth muscle during labor.
Matsumoto
Kenji
K
Department of Allergy and Immunology, National Research Institute for Child Health and Development, Tokyo, Japan. kmatsumoto@nch.go.jp
Ogasawara
Takahisa
T
Kato
Atsushi
A
Homma
Toshiki
T
Iida
Makoto
M
Akasawa
Akira
A
Wakiguchi
Hiroshi
H
Saito
Hirohisa
H
D000293:Adolescent; D000328:Adult; D015550:Cell Degranulation / Q000502:physiology*; D002585:Cesarean Section; D003404:Creatinine / Q000652:urine; D047208:Eosinophil-Derived Neurotoxin; D004804:Eosinophils / Q000502:physiology*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008407:Mast Cells / Q000502:physiology; D008429:Maternal Welfare; D008761:Methylhistamines / Q000652:urine; D011247:Pregnancy / Q000378:metabolism*; D011264:Pregnancy Trimesters / Q000652:urine; D012260:Ribonucleases / Q000652:urine; D013223:Statistics as Topic
D008761:Methylhistamines; D003404:Creatinine; D047208:Eosinophil-Derived Neurotoxin; D012260:Ribonucleases; C048140:N-methylhistamine