Oxytocinase/insulin-regulated aminopeptidase is distributed throughout the sheep, female reproductive tract and is regulated by oestrogen in the uterus.
Using [(125)I]Angiotensin IV (Ang IV) for the autoradiographic localisation of oxytocinase/insulin-regulated aminopeptidase (IRAP), we demonstrate for the first time that IRAP is distributed throughout the female reproductive tract. The highest concentration of IRAP was detected in the outer myometrial layer of the uterus with lower levels in the inner myometrial layer and in the luminal epithelium. High levels of the enzyme was also detected in the inner mucosal lining of the ampulla segment of the fallopian tubes with lower levels in the interstitial and isthmus. In the ovary, a high level of IRAP was found in the corpus albicans with lower levels throughout the ovarian cortex and the surrounding connective tissue. In the uterine body of ovariectomised (OVX) ewes, oestrogen treatment resulted in a significant decrease (P<0.05) in the level of IRAP in the outer myometrium. These findings indicate an important role for IRAP in reproductive physiology in regulating the action of peptide hormones.
Mustafa
Tomris
T
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3010, Australia.
Chai
Siew-Yeen
SY
May
Clive N
CN
Mendelsohn
Frederick A O
FA
Albiston
Anthony L
AL
D000818:Animals; D010122:Cystinyl Aminopeptidase / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology*; D005187:Fallopian Tubes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D005260:Female; D007328:Insulin / Q000494:pharmacology*; D010053:Ovary / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D012756:Sheep; D014599:Uterus / Q000187:drug effects / Q000201:enzymology*
D004967:Estrogens; D007328:Insulin; D010122:Cystinyl Aminopeptidase