Lipid transfer activity in human follicular fluid: Relation to human sperm capacitation
S. E. Ravnik, P. W. Zarutskie, C. H. Muller
Southwestern Graduate School of Biomedical Sciences
A potentially important event during sperm capacitation is the loss of sperm membrane cholesterol. Although the exact mechanisms mediating this loss are not known, albumin and high density lipoprotein have been proposed as lipid acceptors. The authors propose that lipid transfer may be involved in capacitation as a specific mediator in the sequence of events leading to sperm membrane cholesterol loss. We present the first direct evidence of lipid transfer activity (LTA) in human follicular fluid (HFF). The redistribution of 14C-cholesteryl ester among human plasma lipoproteins was used as a measure of LTA (% Transfer [% T]). The HFF was fractionated by S-300 gel filtration chromatography and assayed for LTA. Three peaks of activity were consistently eluted from the column. Each peak of LTA also stimulated human sperm to penetrate zona-free hamster oocytes after short capacitating incubations. The peak with highest LTA (12.75 ± 1.11% T) with an M(r) approximately 68,000, gave the greatest stimulation (penetration index, PI: 3.34 ± 0.96 fold increase above control, n = 4). The HFF also showed a significant dose response for both LTA and PI, whereas bovine serum albumin did not. These results demonstrate the existence of LTA in HFF and suggest that a specific lipid transfer protein may have a role in human sperm capacitation or acrosome reaction.
Journal of Andrology
Sperm Capacitation
Follicular Fluid
Spermatozoa
Acrosome Reaction
Cholesterol Esters
HDL Lipoproteins
Cricetinae
Lipoproteins
Oocytes
Gel Chromatography
capacitation
cholesteryl ester
lipid transfer
sperm penetration assay
Ravnik, S. E., Zarutskie, P. W., & Muller, C. H. (1990). Lipid transfer activity in human follicular fluid: Relation to human sperm capacitation. Journal of Andrology, 11(3), 216-226.
Lipid transfer activity in human follicular fluid : Relation to human sperm capacitation. / Ravnik, S. E.; Zarutskie, P. W.; Muller, C. H.
In: Journal of Andrology, Vol. 11, No. 3, 1990, p. 216-226.
Ravnik, SE, Zarutskie, PW & Muller, CH 1990, 'Lipid transfer activity in human follicular fluid: Relation to human sperm capacitation', Journal of Andrology, vol. 11, no. 3, pp. 216-226.
Ravnik SE, Zarutskie PW, Muller CH. Lipid transfer activity in human follicular fluid: Relation to human sperm capacitation. Journal of Andrology. 1990;11(3):216-226.
Ravnik, S. E. ; Zarutskie, P. W. ; Muller, C. H. / Lipid transfer activity in human follicular fluid : Relation to human sperm capacitation. In: Journal of Andrology. 1990 ; Vol. 11, No. 3. pp. 216-226.
@article{e0d5f0e1f4c64cdfabed0c7ec46709a4,
title = "Lipid transfer activity in human follicular fluid: Relation to human sperm capacitation",
abstract = "A potentially important event during sperm capacitation is the loss of sperm membrane cholesterol. Although the exact mechanisms mediating this loss are not known, albumin and high density lipoprotein have been proposed as lipid acceptors. The authors propose that lipid transfer may be involved in capacitation as a specific mediator in the sequence of events leading to sperm membrane cholesterol loss. We present the first direct evidence of lipid transfer activity (LTA) in human follicular fluid (HFF). The redistribution of 14C-cholesteryl ester among human plasma lipoproteins was used as a measure of LTA ({\%} Transfer [{\%} T]). The HFF was fractionated by S-300 gel filtration chromatography and assayed for LTA. Three peaks of activity were consistently eluted from the column. Each peak of LTA also stimulated human sperm to penetrate zona-free hamster oocytes after short capacitating incubations. The peak with highest LTA (12.75 ± 1.11{\%} T) with an M(r) approximately 68,000, gave the greatest stimulation (penetration index, PI: 3.34 ± 0.96 fold increase above control, n = 4). The HFF also showed a significant dose response for both LTA and PI, whereas bovine serum albumin did not. These results demonstrate the existence of LTA in HFF and suggest that a specific lipid transfer protein may have a role in human sperm capacitation or acrosome reaction.",
keywords = "acrosome reaction, capacitation, cholesteryl ester, follicular fluid, human, lipid transfer, lipids, sperm, sperm penetration assay",
author = "Ravnik, {S. E.} and Zarutskie, {P. W.} and Muller, {C. H.}",
journal = "Journal of Andrology",
publisher = "American Society of Andrology Inc.",
T1 - Lipid transfer activity in human follicular fluid
T2 - Relation to human sperm capacitation
AU - Ravnik, S. E.
AU - Zarutskie, P. W.
AU - Muller, C. H.
N2 - A potentially important event during sperm capacitation is the loss of sperm membrane cholesterol. Although the exact mechanisms mediating this loss are not known, albumin and high density lipoprotein have been proposed as lipid acceptors. The authors propose that lipid transfer may be involved in capacitation as a specific mediator in the sequence of events leading to sperm membrane cholesterol loss. We present the first direct evidence of lipid transfer activity (LTA) in human follicular fluid (HFF). The redistribution of 14C-cholesteryl ester among human plasma lipoproteins was used as a measure of LTA (% Transfer [% T]). The HFF was fractionated by S-300 gel filtration chromatography and assayed for LTA. Three peaks of activity were consistently eluted from the column. Each peak of LTA also stimulated human sperm to penetrate zona-free hamster oocytes after short capacitating incubations. The peak with highest LTA (12.75 ± 1.11% T) with an M(r) approximately 68,000, gave the greatest stimulation (penetration index, PI: 3.34 ± 0.96 fold increase above control, n = 4). The HFF also showed a significant dose response for both LTA and PI, whereas bovine serum albumin did not. These results demonstrate the existence of LTA in HFF and suggest that a specific lipid transfer protein may have a role in human sperm capacitation or acrosome reaction.
AB - A potentially important event during sperm capacitation is the loss of sperm membrane cholesterol. Although the exact mechanisms mediating this loss are not known, albumin and high density lipoprotein have been proposed as lipid acceptors. The authors propose that lipid transfer may be involved in capacitation as a specific mediator in the sequence of events leading to sperm membrane cholesterol loss. We present the first direct evidence of lipid transfer activity (LTA) in human follicular fluid (HFF). The redistribution of 14C-cholesteryl ester among human plasma lipoproteins was used as a measure of LTA (% Transfer [% T]). The HFF was fractionated by S-300 gel filtration chromatography and assayed for LTA. Three peaks of activity were consistently eluted from the column. Each peak of LTA also stimulated human sperm to penetrate zona-free hamster oocytes after short capacitating incubations. The peak with highest LTA (12.75 ± 1.11% T) with an M(r) approximately 68,000, gave the greatest stimulation (penetration index, PI: 3.34 ± 0.96 fold increase above control, n = 4). The HFF also showed a significant dose response for both LTA and PI, whereas bovine serum albumin did not. These results demonstrate the existence of LTA in HFF and suggest that a specific lipid transfer protein may have a role in human sperm capacitation or acrosome reaction.
KW - acrosome reaction
KW - capacitation
KW - cholesteryl ester
KW - follicular fluid
KW - human
KW - lipid transfer
KW - lipids
KW - sperm
KW - sperm penetration assay
JO - Journal of Andrology
JF - Journal of Andrology