This Article Full Text Full Text (PDF) All Versions of this Article: 28/5/698    most recent Author Manuscript (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bronson, R. A. Articles by Oula, L. D. Search for Related Content PubMed PubMed Citation Articles by Bronson, R. A. Articles by Oula, L. D.

Ability of Abnormally-Shaped Human Spermatozoa to Adhere to and Penetrate Zona-Free Hamster Eggs: Correlation With Sperm Morphology and Postincubation Motility

RICHARD A. BRONSON^*,

SUSAN K. BRONSON

LUCILA D. OULA

From the ^* Departments of Obstetrics & Gynecology and Pathology; and the Health Sciences Center, State University of New York at Stony Brook, New York.

Correspondence to: Dr Richard Bronson, Department of Obstetrics & Gynecology, T9-080, Health Sciences Center, SUNY Stony Brook, NY 11794-8091 (e-mail: rbronson{at}notes.cc.sunysb.edu).

A body of evidence indicates that morphologically abnormal human spermatozoa may exhibit impaired ability to fertilize. Yet teratospermia has widely varying etiologies, including associations with varicoceles, following fever, cigarette smoking, and exposure to polychlorinated biphenyls. Abnormalities of sperm shape in mice have also been shown to be associated with autosomal gene mutations. These varying causes of teratospermia could have different molecular consequences reflected in altered sperm function. We studied the ability of morphologically abnormal human sperm to penetrate zona-free hamster eggs as a measure of their ability to undergo an acrosome reaction and gamete membrane fusion. Motile sperm from ejaculates containing 15% normal sperm or less, as judged by World Health Organization (1999) criteria, were recovered by ISolate density centrifugation and capacitated by overnight incubation. Zona-free hamster eggs were inseminated with 1 x 10⁶ motile capacitated cells and scored for sperm penetration after 3 hours of coincubation. A significant trend was found between the percent of abnormal spermatozoa within the ejaculate and impaired egg-penetrating ability, reflected in the percent of eggs penetrated, the number of penetrating sperm per egg, and the number of sperm adherent to the oolemma. Because only acrosome-reacted human spermatozoa adhere to the oolemma, these results support the notion that abnormally shaped sperm may exhibit an impaired ability to undergo an acrosome reaction. A correlation was also noted between the loss of motility of sperm following overnight incubation and impairment of their ability to undergo gamete membrane fusion. These results confirm prior findings at the level of the zona pellucida that abnormally shaped sperm exhibit functional abnormalities. However, a wide variation was observed between men in the behavior of such sperm, including occasionally high rates of egg penetration. These observations suggest that assessment of morphology may be an unreliable measure, for the individual, of sperm fertilizing ability and emphasize that sperm function testing is an important part of the evaluation of teratospermia.

     Key words: Teratospermia, reactive oxygen, fertilization, semen analysis