Experimental Study on Reviability of Cryopreserved Human Spermatozoa

Kim, Kwang Jin; Lee, Moo Sang

Abstract

In order to perform standardization in analytic methods of cryopreserved human semen, to investigate the differences of resistance to cryoinjury, to define the stage of critical cryoinjury during cryopreservation and to evaluate the quality change after thawing by time interval, the reviability of 30 normal and 30 abnormal semen were evaluated by the supravital stainings of spermatozoa using acridine orange and eosin yellow and the motility assay simultaneously according to the stages of freezing-thawing and the time interval after thawing. The results were summarized as follows: 1. Vitality was estimated higher than motility at all specimens and the gap between two became greater as motility decreased. 2. Reviability of abnormal semen was estimated lower than that of normal semen(p<0.05). 3. The critical cryoinjury to spermatozoa was noticed at the stage of freezing from 4 degrees C to -10 degrees C (p<0.05). 4. The significant decrease in quality of normal cryopreserved semen was noticed between 30 to 60 min. after thawing (p<0.05). These results suggest that the cryoinjury to human semen is different in nature, therefore it is advisable that the quality of cryopreserved human semen should be evaluated by vitality and motility assay simultaneously. And the resistance of abnormal semen to cryopreservation is so low that it would be difficult to be used clinically with satisfaction. Moreover the laboratory studies should be concentrated on freezing method to achieve better reviability and it is desirable in practice that post-thaw semen should be used within 30 min, after thawing.