Expression of nitric oxide synthase isoforms in human pregnant myometrium at term.
OBJECTIVE
To determine whether nitric oxide synthase isoforms are expressed in human myometrium, to define their localization, and to examine the possibility that one or more may play a role in initiating labor.


METHODS
Human myometrial biopsies were collected from term laboring and nonlaboring patients. The mRNA expression was assessed using in situ hybridization. The relative expression levels were also assessed by Affymetrix GeneChip hybridization. The protein expression was determined using Western blot analysis, and localization was shown using immunostaining.


RESULTS
Both inducible nitric oxide synthase and brain nitric oxide synthase were expressed in myometrial cells and blood vessel endothelial cells. Endothelial nitric oxide synthase was expressed exclusively in blood vessel endothelial cells. There were no differences in distribution or quantity of nitric oxide synthase expression between term labor and nonlabor myometrium.


CONCLUSIONS
All three isotypes of nitric oxide synthases were expressed in human pregnant term uterus. Their expression did not change in the myometrium of the laboring uterus.
Bao
Shunzhong
S
Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. bao@borcim.wustl.edu
Rai
Jodie
J
Schreiber
James
J
D015153:Blotting, Western; D004730:Endothelium, Vascular / Q000201:enzymology; D005260:Female; D015870:Gene Expression; D006801:Humans; D017403:In Situ Hybridization; D007743:Labor, Obstetric / Q000502:physiology*; D009215:Myometrium / Q000201:enzymology*; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis; D012984:Software
D012333:RNA, Messenger; C496320:NOS1 protein, human; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III