Expression of phosphodiesterase 5 in maternal and fetal sheep.
OBJECTIVE
Ovine pregnancy is associated with elevated levels of nitric oxide. Nitric oxide stimulates cyclic guanosine monophosphate (cGMP), which results in vascular smooth muscle relaxation/vasodilation. Phosphodiesterase type 5 regulates cGMP in the urogenital track. The present study was designed to determine message expression of phosphodiesterase type 5 in the myometrium, uterine vessels, and placentome of the sheep and phosphodiesterase type 5 protein expression in the maternal and fetal placentome.


METHODS
Tissue was collected from 5 nonpregnant and 5 pregnant anesthetized animals (gestational day = 134 +/- 4) and frozen at -80 degrees C. Optimized reverse transcription-polymerase chain reaction was performed on all tissues, and immunohistochemistry was performed on the placentome only.


RESULTS
Phosphodiesterase type 5 messenger ribonucleic acid levels were significantly higher in the myometrium and placentome, compared with the maternal blood vessels. Phosphodiesterase type 5 protein was immuno-localized to the vascular smooth muscle of the maternal vessels, stroma, and placental capsule only.


CONCLUSIONS
Although phosphodiesterase type 5 messenger ribonucleic acid was present in the fetal placenta, phosphodiesterase type 5 protein was expressed only in maternally derived placental tissue. This suggests that regulation of cGMP levels and vascular tone in the umbilical circulation differs from the uterine circulation.
Coppage
Kristin H
KH
Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Cincinnati, Cincinnati, OH, USA. kcoppage@fuse.net
Sun
XuMing
X
Baker
R Scott
RS
Clark
Kenneth E
KE
D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000818:Animals; D006152:Cyclic GMP / Q000502:physiology; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D005260:Female; D005312:Fetal Blood / Q000502:physiology*; D007150:Immunohistochemistry; D009215:Myometrium / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D012039:Regional Blood Flow / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep; D014599:Uterus / Q000098:blood supply*
D012333:RNA, Messenger; D010727:Phosphoric Diester Hydrolases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D006152:Cyclic GMP