Oxytocinase is a type of enzyme that metabolizes the endogenous neuropeptide, oxytocin.[1] The most well-characterized oxytocinase is leucyl/cystinyl aminopeptidase,[1][2] which is also an enkephalinase. Other oxytocinases are also known.[1][3] During pregnancy, oxytocinase plays a role in balancing concentration of oxytocin by degrading the oxytocin produced by the fetus, as production of oxytocin increases with growth of fetus.[2] One study found that concentration level of oxytocinase increased progressively with gestational age until labor, which indicates that pregnancy development can be statistically evaluated by comparing oxytocinase levels.[4]
Amastatin, bestatin (ubenimex), and puromycin have been found to inhibit the enzymatic degradation of oxytocin, though they also inhibit the degradation of various other peptides, such as vasopressin, met-enkephalin, and dynorphin A.[5][3][6] EDTA, L-methionine, o-phenanthroline, and phosphoramidon have also been found to inhibit the enzymatic degradation of oxytocin.[7]