The purpose of this study was to determine to what degree bacterial
collagenase may digest human placentae compared to equine and bovine placentae. Placenta samples from human, equine and bovine were incubated with bacterial
collagenase solution at various concentrations. The degree of hydrolysis and
collagen breakdown was measured by the release of total
proteins and
hydroxyproline into the incubation media. Also, whole placentae were injected via umbilical cord arteries with
collagenase solution (200 U/ml, 200 ml total volume in human and 1000 ml in equine) and hydrolysis determined chemically and subjectively. Human and equine placental
collagens were the most sensitive to
collagenase digestion. Overall mean
collagenase activity determined by the release of
hydroxyproline from human placenta was 1.6 times and in equine placenta three times greater than in bovine placenta, while the breakdown of non-collagenous
proteins remained negligible. When injected into whole placenta, the
collagenase digested placentae evenly within 6-12 h. At 24 h, placentae were liquefied, although, umbilical blood vessels resisted
collagenase digestion. Bacterial
collagenase was highly effective in breaking down human placenta
collagen. Intraplacental
injections of
collagenase via umbilical cord arteries may help to detach
retained placenta in women as it does in mares and cows.