| Autor: |
S, Benoff, G W, Cooper, I, Hurley, F S, Mandel, D L, Rosenfeld, G M, Scholl, B R, Gilbert, A, Hershlag |
| Rok vydání: |
1994 |
| Předmět: |
|
| Zdroj: |
Fertility and sterility. 62(3) |
| ISSN: |
0015-0282 |
| Popis: |
To evaluate the effects of calcium ion (Ca2+) channel blockers on male fertility potential.A case comparison of the surface expression of mannose-ligand receptors on motile spermatozoa from 10 known fertile males and from 10 normospermic men taking Ca2+ channel blockers who were seeking infertility treatment. Examination of the effects of in vitro exposure of sperm from fertile donors (n = 14) to antihypertensive medications.Patients from a successful university hospital-based IVF-assisted reproductive technology program and from a male urology private practice.Prescription of alternate hypotensive medications for four male patients; cholesterol loading and unloading in vitro of fertile donor sperm.Motile sperm were tested for their ability to bind fluorescein isothiocyanate-labeled, mannosylated bovine serum albumin as an index of the surface expression of mannose-ligand receptors associated with fertility potential. Acrosome status was simultaneously evaluated by fluorescence microscopy with rhodamine-labeled Pisum sativum lectin. Sperm were assayed before and after an 18-hour or 3-day incubation under capacitating conditions in vitro.Motile spermatozoa of normospermic men taking calcium antagonists for hypertension control do not express head-directed mannose-ligand receptors at high frequency, nor do they undergo spontaneous acrosome loss. Unexpectedly, mannose-ligand receptor translocation from the subplasmalemmal space over the acrosome to the sperm surface and aggregation over the equatorial-postacrosomal regions occurred in acrosome-intact sperm. This differs from fertile controls in whom receptor translocation to the equatorial-postacrosomal segment is coupled with the acrosome reaction (AR). Discontinuation of calcium antagonists results in complete recovery of parameters associated with sperm fertilizing potential: time-dependent increases in the percentages of spermatozoa exhibiting surface mannose-ligand binding and spontaneous ARs in vitro. The effects of in vivo administration of calcium antagonists is mimicked in control fertile donor sperm by inclusion of a Ca2+ channel blocker in the media employed during capacitating incubations.Therapeutic administrations of calcium antagonists for hypertension control cause reversible male infertility associated with an IVF failure. A mechanism of inhibition of sperm fertilizing potential through insertion of lipophilic calcium ion antagonists into the lipid bilayer of the sperm plasma membrane is consistent with our in vitro studies. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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