title: In vitro decondensation of human sperm chromatin.
abstract: The swelling of human sperm head and the decondensation of the sperm chromatin were investigated using a microscopic observation and the increased binding of AMD as the probes. Incubation of the human spermatozoa with 1 mM DTT produced sperm head swelling within 30 min. Addition of soybean trypsin inhibitor or PMSF blocked the swelling induced by 1 mM DTT. The DTT induced a large increase in the binding of AMD to the spermatozoa, to the sperm head and to the triton X-100 treated spermatozoa. This increase in AMD binding was completely abolished by the presence of PMSF. These results suggested the participation of a sulfhydryl reducing agent and a proteolytic enzyme in the sperm head swelling and the chromatin decondensation. The simplicity of probing the chromatin decondensation with AMD binding offers a means to study kinetic and quantitative aspects of the process.
mesh_terms: D001665:Binding Sites; D002843:Chromatin / Q000502:physiology*; D003609:Dactinomycin / Q000378:metabolism; D004229:Dithiothreitol / Q000494:pharmacology*; D005260:Female; D005306:Fertilization; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D013077:Sperm Head / Q000187:drug effects* / Q000502:physiology; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D002843:Chromatin; D003609:Dactinomycin; D014357:Trypsin; D004229:Dithiothreitol