Eiler H, Hopkins F M
Agricultural Experiment Station, University of Tennessee, Knoxville 37901-1071.
Biol Reprod. 1992 Apr;46(4):580-5. doi: 10.1095/biolreprod46.4.580.
A significant percentage of cows (11%) fail to release the placenta within 12 h postpartum. Failure of collagen breakdown seems to be related to the retention of placentas. Sections of placentomes incubated with bacterial collagenase caused an increase in placentome proteolysis (6.6-fold) and placentome collagenolysis (94-fold) within 4 h in a dose-related fashion (r = 0.94). Injections of collagenase (825 U/cc) into the placentomes, via umbilical vessels, decreased the cotyledon-caruncle binding force (determined by manometry) to 30 +/- 5 mm Hg from 97 +/- 2 mm Hg, and increased proteolysis by 42% within 8 h (r = -0.95). Hyaluronidase at various concentrations (400-8 250 U/cc) and at various incubation times (up to 8 h) was not effective. Hyaluronidase (825 U/cc) and collagenase (825 U/cc) were not synergistic in loosening cotyledon-caruncle attachment. A single 15-min collagenase pulse, given prior to perfusion with collagenase-free blood, was as effective in loosening cotyledon attachment as was a sustained 2-h perfusion of blood with collagenase added. It was concluded that collagenase caused collagenolysis and loosening of cotyledon from caruncle, but collagenolysis and cotyledon-caruncle separation were not facilitated by the presence of hyaluronidase.
相当比例的奶牛（11%）在产后12小时内未能排出胎盘。胶原蛋白分解失败似乎与胎盘滞留有关。用细菌胶原酶孵育胎盘小叶切片，4小时内胎盘小叶蛋白水解（6.6倍）和胎盘小叶胶原水解（94倍）呈剂量相关增加（r = 0.94）。通过脐血管向胎盘小叶注射胶原酶（825 U/cc），使子叶 - 肉阜结合力（通过压力测定法测定）从97±2毫米汞柱降至30±5毫米汞柱，并在8小时内蛋白水解增加42%（r = -0.95）。不同浓度（400 - 8250 U/cc）和不同孵育时间（长达8小时）的透明质酸酶均无效。透明质酸酶（825 U/cc）和胶原酶（825 U/cc）在松开子叶 - 肉阜附着方面没有协同作用。在无胶原酶血液灌注前给予单次15分钟的胶原酶脉冲，在松开子叶附着方面与添加胶原酶的血液持续灌注2小时同样有效。得出的结论是，胶原酶导致胶原蛋白分解以及子叶与肉阜松开，但透明质酸酶的存在并未促进胶原蛋白分解和子叶 - 肉阜分离。
