Studies on the mechanism of edematous changes at the endometrial stroma for implantation.
The endometrium undergoes edematous changes during the implantation period. Many factors may be involved in these biochemical reactions. We investigated the localization of inducible NO synthase (iNOS), interleukin-8 (IL-8), mast cell tryptase, neutrophil elastase, type III collagen, and CD44 in human endometrium. Immunohistochemical staining was performed by the labeled streptavidin-biotin method. iNOS was stained in the entire endometrial tissue from the midproliferative phase. The IL-8-positive cells, mast cells, and neutrophil elastase in the stroma increased toward the early to midsecretory phase. Type III collagen was arranged regularly in the stromal extracellular matrix during the proliferative phase; however, it was dissected during the secretory phase. CD44 was detected around stromal cells in the midsecretory phase. From these results, we propose the following mechanism. Initially, iNOS, expressed by the entire endometrial tissues from the midproliferative phase, catalyzes the production of NO. NO stimulates cells, supposed to be mast cells, to produce IL-8, which lets neutrophils migrate into the stroma. Neutrophils secrete elastase, which degrades type III collagen, generating spaces in the stroma. Hyaluronic acid adheres to CD44 around the stromal cells and retains water intermolecularly, finally forming the edematous matrix.
Okada
Y
Y
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Shizuoka, Japan.
Asahina
T
T
Kobayashi
T
T
Goto
J
J
Terao
T
T
D000328:Adult; D024061:Collagen Type III / Q000502:physiology; D004487:Edema / Q000473:pathology / Q000503:physiopathology; D010064:Embryo Implantation; D047108:Embryonic Development / Q000502:physiology*; D004717:Endometrium / Q000166:cytology / Q000502:physiology*; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000502:physiology; D016209:Interleukin-8 / Q000502:physiology; D019272:Leukocyte Elastase / Q000502:physiology; D008597:Menstrual Cycle; D019001:Nitric Oxide Synthase / Q000502:physiology; D052247:Nitric Oxide Synthase Type II; D011247:Pregnancy; D012697:Serine Endopeptidases / Q000502:physiology; D017154:Stromal Cells / Q000502:physiology; D053802:Tryptases
D024061:Collagen Type III; D018960:Hyaluronan Receptors; D016209:Interleukin-8; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D012697:Serine Endopeptidases; D019272:Leukocyte Elastase; D053802:Tryptases