Evaluation of human sperm function after being cryopreserved within the zona pellucida
Received 8 April 2008; received in revised form 5 July 2008; accepted 15 July 2008. published online 01 October 2008.
Objective
To investigate the fertilization ability, chromatin structure, and DNA integrity of spermatozoa after being cryopreserved within an empty zona pellucida (ZP).
Design
Prospective study.
Setting
Reproductive research center in a university-affiliated hospital.
Patient(s)
Normozoospermic patients.
Intervention(s)
Spermatozoa were cryopreserved within the ZP or with traditional methods.
Main Outcome Measure(s)
The sperm recovery rate, sperm motility, fertilization ability, chromatin structure, and DNA integrity were assessed before and after cryopreservation.
Result(s)
Significantly higher sperm recovery rate was identified for the spermatozoa cryopreserved within the ZP than those cryopreserved with traditional methods, but the motility recovery was similar. Frozen-thawed samples showed increased damage to the sperm chromatin and DNA, which were assessed by acridine orange test (AO) and terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling assay; however, no difference of chromatin and DNA integrity was observed for spermatozoa cryopreserved within the ZP or with traditional methods. In addition, the fertilization ability, as assessed by injecting spermatozoa into hamster oocytes, was similar for spermatozoa cryopreserved with different cryopreservation methods.
Conclusion(s)
Cryopreservation of spermatozoa within an empty ZP results in higher sperm recovery rate, and the post-thaw sperm functions of spermatozoa cryopreserved within the ZP are comparable with spermatozoa cryopreserved with traditional methods.
Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
Reprint requests: Hefeng Huang, M.D., Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 31006, China (FAX: 86-571-87217044).
Y.Y. has nothing to disclose. C.X. has nothing to disclose. Y.Q. has nothing to disclose. F.J. has nothing to disclose. H.H. has nothing to disclose.
Supported by the National 863 program (grant No. 20060102A1022 & 2007AA02Z456), National 973 program (2006CB504004 & 2006CB944006), the Health Bureau of Zheijiang Province (grant No. 2004QN015) and the National Science Foundation of China (grant No. 30300371).
ABSTRACT