输精管注射高分子聚合物HFMC的非堵塞性化学避孕及其生育可复性的动物实验研究

Animal Experiments of a Non-occlusion Device for Reversible Male Contraception Following High Molecular Polymer HFMC Intra Vas Deferens Injection

本实验利用兔、SD大鼠及昆明种小鼠进行输精管注入高分子聚合物HFMC,起到有效杀精子避孕作用。通过精子质量检测,判断避孕有效性及避孕时程,并证实与注入的浓度和剂量相关。应用雄雌配对实验,观察到自然复孕,而且复孕率与注入浓度成负相关。在兔50％实验组,观察到复孕过程的20个月中有三个时相,其复孕率为40％,人工复孕与对照组无显著差异(P>0.05)。

A single dose injection of high molecular polymer HFMC, a tissue adhesive, into the vasal lumen of adult male rabbits, SD rats,and Kunming species mice resulted in temporarly vas deferens occlusion, which contributed most effectively toward contraception. The occlusion time was positively correlated to the concentration of HFMC. While the polymer dissolved itself gradually, the sperm vitality recovered progressively so that fertility was resumed naturally. The resuming fertility was negatively correlated to the concentration of HFMC. The reversible process of rabbits given 5% HFMC intra-vas was discovered in three phases by means of progressive observation of fertility index, that is, no fertility during the 1st 8 months following injection, low fertility during 9th-14th month after the injection and resuming fertility in the 18-20th month. The fertility rate was 40% in 5% HFMC intra-vas groups. The amount of semen, density of sperm, degrees of sperm motility,malformation rate and velocity of forward motility were all determined by sperm mortality, or routine method set by WHO. All data obtained wereanalyzed with 2 multidimentional scale equations, which were established in our previous studies according to the normal reference range of healthyfetile male rabbits. In 27 of 42 male rabbits given high dosage(20-40)mgintra-vasal injection per side no recovery of fertility was found.In rats we could find the rate of fertility recovery was directly related to the concentration of HFMC, that. is in the 7.5% HFMC group recovery rate was 100% within one year, but in the 20% HFMC group was only 25% within the same period. So that HFMC possessed contraceptive effects which lasted longer as the concentration of given HFMC increased.In the mice, the copolymer HFMC was introduced through a small tube into the vagina. The sperm were killed or/and lost their moving ability which resulted in infertility. The fertility could be restored when the HFMC dissolved itself gradually so that the delivering time was delayed about 112-118 days versus the control(p<0.001). It also could be restored artificially by flushing out the copolymer with solvent DMSO. In that case the delivering time was consistent with the control (p>0.05). The new-borns delivered by those experimental animals were oufnd to be grossly non-defective.