OBJECTIVE: To evaluate changes that occur in sperm plasma membranes during capacitation, the internalization of [(3)H]lyso-platelet activating factor ([(3)H]lyso-PAF) across the plasma membrane of human spermatozoa was measured as a function of incubation time or exposure to progesterone (P). DESIGN: In vitro cell culture study using human spermatozoa. SETTING: Department of Obstetrics and Gynecology, School of Medicine, the University of Tokushima, Japan. PATIENT(S): Semen were obtained from three fertile healthy volunteers. INTERVENTION(S): The internalization of [(3)H]lyso-PAF across the plasma membranes of human spermatozoa that were incubated for an extended period or exposed to P was measured at 5, 20, 60, and 120 minutes after the addition of the phospholipid probe using the modified albumin back-exchange method. MAIN OUTCOME MEASURE(S): The percentage of capacitated and acrosome-reacted sperm and the proportion of internalization of lyso-PAF across the plasma membrane. RESULT(S): A 6-hour incubation period significantly increased the percentage of capacitated spermatozoa and the proportion of internalization of [(3)H]lyso-PAF across the plasma membrane of human spermatozoa compared with controls (capacitated spermatozoa, 20.3 +/- 10.6% vs. 8.5 +/- 1.8%; internalization 120 minutes after the addition of the phospholipid probe, 25.6 +/- 2.5% vs. 11.6 +/- 3.0%) (mean +/- SEM). Exposure to P significantly increased the percentage of capacitated spermatozoa compared with controls (19.6 +/- 6.8% vs. 11.0 +/- 2.4%) and also significantly accelerated the internalization of [(3)H]lyso-PAF compared with controls (internalization 120 minutes after the addition of the phospholipid probe, 26.2 +/- 1.8% vs. 21.4 +/- 1.1%). CONCLUSION(S): The administration of P or a long incubation increased the proportion of internalization and consequently induced capacitation in human spermatozoa.
OBJECTIVE: To evaluate changes that occur in sperm plasma membranes during capacitation, the internalization of [(3)H]lyso-platelet activating factor ([(3)H]lyso-PAF) across the plasma membrane of human spermatozoa was measured as a function of incubation time or exposure to progesterone (P). DESIGN: In vitro cell culture study using human spermatozoa. SETTING: Department of Obstetrics and Gynecology, School of Medicine, the University of Tokushima, Japan. PATIENT(S): Semen were obtained from three fertile healthy volunteers. INTERVENTION(S): The internalization of [(3)H]lyso-PAF across the plasma membranes of human spermatozoa that were incubated for an extended period or exposed to P was measured at 5, 20, 60, and 120 minutes after the addition of the phospholipid probe using the modified albumin back-exchange method. MAIN OUTCOME MEASURE(S): The percentage of capacitated and acrosome-reacted sperm and the proportion of internalization of lyso-PAF across the plasma membrane. RESULT(S): A 6-hour incubation period significantly increased the percentage of capacitated spermatozoa and the proportion of internalization of [(3)H]lyso-PAF across the plasma membrane of human spermatozoa compared with controls (capacitated spermatozoa, 20.3 +/- 10.6% vs. 8.5 +/- 1.8%; internalization 120 minutes after the addition of the phospholipid probe, 25.6 +/- 2.5% vs. 11.6 +/- 3.0%) (mean +/- SEM). Exposure to P significantly increased the percentage of capacitated spermatozoa compared with controls (19.6 +/- 6.8% vs. 11.0 +/- 2.4%) and also significantly accelerated the internalization of [(3)H]lyso-PAF compared with controls (internalization 120 minutes after the addition of the phospholipid probe, 26.2 +/- 1.8% vs. 21.4 +/- 1.1%). CONCLUSION(S): The administration of P or a long incubation increased the proportion of internalization and consequently induced capacitation in human spermatozoa.
Authors: Héctor Alejandro Guidobaldi; María Eugenia Teves; Diego Rafael Uñates; Agustín Anastasía; Laura Cecilia Giojalas Journal: PLoS One Date: 2008-08-22 Impact factor: 3.240