Fahim M S, Wang M, Sutcu M F, Fahim Z, Youngquist R S
Center of Reproductive Science and Technology, University of Missouri, Columbia.
Contraception. 1993 Jan;47(1):107-22. doi: 10.1016/0010-7824(93)90113-l.
Condoms and vasectomy are the only fertility control methods available to males. Fifty million surgical vasectomies have been performed worldwide. In spite of improvements in the surgical techniques, the widespread use of vasectomy is limited due mainly to fear of genital operation. Chemical sterilization offers a promising new approach as an alternative to surgery. Fifteen sexually mature, mixed breed, male dogs, 2-3 1/2 years of age and weighing 22 +/- 1.8 kg, were divided into two groups. Five control placebo animals were injected with 0.5 ml of saline into the cauda epididymis, and ten treated animals were injected with 0.5 ml of 50 mg of zinc arginine into the cauda epididymis. Semen analysis performed before injection showed no significant difference between control placebo and treated groups. The control placebo animals exhibited a significant reduction in sperm motility one month after injection, which returned to normal within two months, and no change in semen volume, sperm abnormalities, or sperm concentration analyzed monthly for twelve months. The zinc arginine-treated animals achieved azoospermia ninety days after injection. The dogs were sacrificed one year after injection. There was no significant reduction of reproductive organ weights of the treated group as compared to the control placebo group. Although histological examination of the testes revealed normal seminiferous tubules, there was atrophy of the rete testes of the zinc arginine-treated group and, thus, increase in connective tissue. Histological examination of epididymides of the zinc arginine-treated group indicated that none of the cells in the head, body, and tail of the epididymis and ductus deferens contained sperm; 90% of the coils were empty and 10% contained amorphous pink cell debris; the coils decreased in diameter and were lined by cuboidal to columnar epithelium; no granuloma was observed. There was no significant change in serum testosterone level of control placebo and treated groups. These results offer the possibility of a new method of permanent sterilization instead of surgery. Zinc is considered to be nonmutagenic, noncarcinogenic, and nonteratogenic.
避孕套和输精管切除术是男性仅有的生育控制方法。全球已进行了5000万例输精管切除手术。尽管手术技术有所改进，但输精管切除术的广泛应用仍受到限制，主要原因是人们对生殖器手术存在恐惧。化学绝育作为一种替代手术的新方法，前景广阔。15只性成熟的杂种公犬，年龄在2至3岁半之间，体重22±1.8千克，被分为两组。5只对照安慰剂动物在附睾尾部注射0.5毫升生理盐水，10只治疗动物在附睾尾部注射0.5毫升含50毫克精氨酸锌的溶液。注射前进行的精液分析显示，对照安慰剂组和治疗组之间无显著差异。对照安慰剂动物在注射后1个月精子活力显著降低，2个月内恢复正常，在随后的12个月里每月分析精液量、精子异常或精子浓度均无变化。精氨酸锌治疗的动物在注射后90天达到无精子症。注射1年后处死这些犬。与对照安慰剂组相比，治疗组生殖器官重量无显著减轻。尽管睾丸的组织学检查显示生精小管正常，但精氨酸锌治疗组的睾丸网萎缩，结缔组织增加。精氨酸锌治疗组附睾的组织学检查表明，附睾头、体、尾以及输精管中的细胞均未发现精子；90%的附睾管为空，10%含有无定形粉红色细胞碎片；附睾管直径减小，内衬为立方上皮至柱状上皮；未观察到肉芽肿。对照安慰剂组和治疗组的血清睾酮水平无显著变化。这些结果为一种替代手术的永久性绝育新方法提供了可能性。锌被认为无致突变性、无致癌性且无致畸性。
