Lane V M, Liu I K M, Casey K, vanLeeuwen E M G, Flanagan D R, Murata K, Munro C
Department of Population Health and Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA.
Reprod Fertil Dev. 2007;19(5):617-25. doi: 10.1071/rd06154.
The present 2-year study investigated the feasibility of using porcine zona pellucidae (pZP) as antigen for immunocontraception in American black bears. Sows, 3-6 years of age, were administered either two doses of 250 microg pZP with Freund's adjuvant (n = 10) or adjuvant alone (n = 5), one in April and one in May, and were kept away from the boars until June. Serum samples were collected before injections and before denning (November). The presence of sows with cubs at side was observed during premature emergence from denning. First-year results indicated that anti-pZP antibody titres in vaccinated sows were 2.5-9.0-fold (range) higher compared with non-vaccinated sows and that the vaccinated sows were threefold less likely to become pregnant (P = 0.167). Control and vaccinated bears produced 1.6 and 0.2 cubs per sow, respectively (P = 0.06). The second-year study investigated the feasibility of using pZP sequestered in a controlled-release pellet and a water-soluble adjuvant (QS-21) to avoid regulatory problems associated with Freund's adjuvant. Sows in the treatment group (n = 22) were administered a single dose of an emulsion of 250 microg pZP and 150 microg QS-21 plus a pellet containing 70-90 microg pZP for delayed release as booster dose. Control sows (n = 5) received the QS-21 adjuvant in pellet alone. Serum samples were collected before inoculations (April) and before denning (November). Seven cubs were born to the five control sows, but none was born to the 22 vaccinated sows (P < 0.001). Anti-pZP antibody mean absorbance ratios in control sows remained at background levels, whereas vaccinated sows had ratios fourfold higher than controls. Two-dimensional polyacrylamide gel electrophoresis and immunohistochemical localisation confirmed immunoreactivity of sera from inoculated bears. We conclude that cub production in the American black bear can be effectively limited with either two injections of 250 microg pZP or a single inoculation of partially purified pZP sequestered in controlled-release pellets.
本为期两年的研究调查了将猪透明带（pZP）用作美洲黑熊免疫避孕抗原的可行性。选取3至6岁的母猪，一组10头母猪于4月和5月分别注射两剂250微克pZP与弗氏佐剂，另一组5头母猪仅注射佐剂，之后这些母猪与公猪隔离直至6月。在注射前和入蛰前（11月）采集血清样本。在提前出蛰期间观察母猪身旁幼崽的情况。第一年的结果表明，与未接种的母猪相比，接种疫苗的母猪体内抗pZP抗体滴度高2.5至9.0倍（范围），且接种疫苗的母猪怀孕几率降低了三分之一（P = 0.167）。对照组和接种疫苗组的母猪每头分别产下1.6头和0.2头幼崽（P = 0.06）。第二年的研究调查了使用包埋于控释微丸中的pZP和水溶性佐剂（QS - 21）以避免与弗氏佐剂相关的监管问题的可行性。治疗组的22头母猪接受了一剂含250微克pZP和150微克QS - 21的乳剂注射，外加一粒含70 - 90微克pZP的控释微丸作为加强剂量。对照组的5头母猪仅接受含QS - 21佐剂的微丸。在接种前（4月）和入蛰前（11月）采集血清样本。5头对照母猪共产下7头幼崽，但22头接种疫苗的母猪均未产仔（P < 0.001）。对照母猪的抗pZP抗体平均吸光度比值维持在背景水平，而接种疫苗的母猪该比值比对照组高四倍。二维聚丙烯酰胺凝胶电泳和免疫组织化学定位证实了接种熊血清的免疫反应性。我们得出结论，通过两次注射250微克pZP或单次接种包埋于控释微丸中的部分纯化pZP，可有效限制美洲黑熊的幼崽数量。
