OBJECTIVE: To evaluate the acrosome reaction and its prerequisite, a calcium influx, in spermatozoa of infertile men with a high incidence of abnormal sperm forms. DESIGN: Prospective, controlled study. SETTING: Academic tertiary assisted reproduction center. PATIENTS: Patients (n = 14) were allocated in the study after semen evaluation showed teratozoospermia (< 14% normal sperm forms) as diagnosed by strict criteria. INTERVENTIONS: After swim-up separation of the motile fraction, acrosome reactions were evaluated using Pisum sativum agglutinin (both spontaneously and exogenously induced with P and the calcium ionophore A23187, both at 10 microM); the intracellular-free [Ca2+]i was assessed by the fluorescent fura-2 indicator (basal and after P). RESULTS: Patients did not show the typical P-induced wave of [Ca2+]i that was observed in controls but rather a blunted response, no response at all, or abnormal basal [Ca2+]i levels. The percent of basal acrosome reaction was significantly lower for patients versus controls postswim-up, and at 1 hour and 3 hours. Furthermore, there was a significant difference in the response of acrosome reaction to P both at 1 hour and 3 hours, with patients showing almost no response at all. However, patients' acrosome reaction response to the calcium ionophore was similar to those of fertile men. CONCLUSION: Infertile patients with a high incidence of abnormal sperm forms as diagnosed by strict criteria have a low incidence of spontaneous acrosome reaction and a diminished P-stimulated acrosome reaction, whereas the nonspecific response to a calcium ionophore is conserved. Parallel abnormalities of [Ca2+]i were observed in patients, suggesting that these sperm populations may have a defective nongenomic P sperm receptor and/or abnormalities of other membrane transduction systems.
OBJECTIVE: To evaluate the acrosome reaction and its prerequisite, a calcium influx, in spermatozoa of infertilemen with a high incidence of abnormal sperm forms. DESIGN: Prospective, controlled study. SETTING: Academic tertiary assisted reproduction center. PATIENTS: Patients (n = 14) were allocated in the study after semen evaluation showed teratozoospermia (< 14% normal sperm forms) as diagnosed by strict criteria. INTERVENTIONS: After swim-up separation of the motile fraction, acrosome reactions were evaluated using Pisum sativum agglutinin (both spontaneously and exogenously induced with P and the calcium ionophore A23187, both at 10 microM); the intracellular-free [Ca2+]i was assessed by the fluorescent fura-2 indicator (basal and after P). RESULTS:Patients did not show the typical P-induced wave of [Ca2+]i that was observed in controls but rather a blunted response, no response at all, or abnormal basal [Ca2+]i levels. The percent of basal acrosome reaction was significantly lower for patients versus controls postswim-up, and at 1 hour and 3 hours. Furthermore, there was a significant difference in the response of acrosome reaction to P both at 1 hour and 3 hours, with patients showing almost no response at all. However, patients' acrosome reaction response to the calcium ionophore was similar to those of fertile men. CONCLUSION: Infertile patients with a high incidence of abnormal sperm forms as diagnosed by strict criteria have a low incidence of spontaneous acrosome reaction and a diminished P-stimulated acrosome reaction, whereas the nonspecific response to a calcium ionophore is conserved. Parallel abnormalities of [Ca2+]i were observed in patients, suggesting that these sperm populations may have a defective nongenomic P sperm receptor and/or abnormalities of other membrane transduction systems.
Authors: Hannah L Williams; Steven Mansell; Wardah Alasmari; Sean G Brown; Stuart M Wilson; Keith A Sutton; Melissa R Miller; Polina V Lishko; Christopher L R Barratt; Steven J Publicover; Sarah Martins da Silva Journal: Hum Reprod Date: 2015-10-08 Impact factor: 6.918