H M Youssef1, G F Doncel, B A Bassiouni, A A Acosta. 1. Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk 23507, USA.
Abstract
OBJECTIVE: To verify a possible association between the expression of sperm head mannose-binding sites and sperm morphology. DESIGN: Prospective in vitro study. SETTING: University-based sperm biology and andrology laboratories. PARTICIPANTS: Twenty-seven fertile donors and 45 patients consulting for infertility. INTERVENTIONS: D-mannose-binding sites were identified using a fluoresceinated mannose-enriched bovine serum albumin. Hoechst 33258 was included to confirm sperm viability and hypo-osmotic swelling test to assess plasma membrane integrity. Sperm morphology was judged by strict criteria and semen samples were classified into three groups: normal (group N, > 10% morphologically normal sperm, n = 27), good prognosis (group G, 5% to 10%, n = 23), or poor prognosis (group P, < or = 4%, n = 22). RESULTS: Only viable (Hoechst 33258 negative) spermatozoa with intact plasma membrane (hypo-osmotic swelling test positive)were considered in the evaluation of mannose-binding sites. The incidence of spermatozoa showing surface mannose-binding sites was higher in the N group (48.1% +/- 1.9%; mean +/- SEM) then in the G (17.6% +/- 4.4%) or P (7.6% +/- 2.3%) groups. Total mannose-binding site expression and percentage of morphologically normal sperm showed a high positive correlation (r = 0.80). CONCLUSION: Altered expression of mannose-binding sites, putative zona receptors, may be one of the molecular defects causing decreased fertility in morphologically abnormal human sperm.
OBJECTIVE: To verify a possible association between the expression of sperm head mannose-binding sites and sperm morphology. DESIGN: Prospective in vitro study. SETTING: University-based sperm biology and andrology laboratories. PARTICIPANTS: Twenty-seven fertile donors and 45 patients consulting for infertility. INTERVENTIONS:D-mannose-binding sites were identified using a fluoresceinated mannose-enriched bovine serum albumin. Hoechst 33258 was included to confirm sperm viability and hypo-osmotic swelling test to assess plasma membrane integrity. Sperm morphology was judged by strict criteria and semen samples were classified into three groups: normal (group N, > 10% morphologically normal sperm, n = 27), good prognosis (group G, 5% to 10%, n = 23), or poor prognosis (group P, < or = 4%, n = 22). RESULTS: Only viable (Hoechst 33258 negative) spermatozoa with intact plasma membrane (hypo-osmotic swelling test positive)were considered in the evaluation of mannose-binding sites. The incidence of spermatozoa showing surface mannose-binding sites was higher in the N group (48.1% +/- 1.9%; mean +/- SEM) then in the G (17.6% +/- 4.4%) or P (7.6% +/- 2.3%) groups. Total mannose-binding site expression and percentage of morphologically normal sperm showed a high positive correlation (r = 0.80). CONCLUSION: Altered expression of mannose-binding sites, putative zona receptors, may be one of the molecular defects causing decreased fertility in morphologically abnormal human sperm.