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Biomedical subjects

M Zorzi

Publications and source records attributed to M Zorzi.

22 records · Page 2Linked to original sources
PubMedDate not supplied

Progesterone induces capacitation in human spermatozoa.

Mammalian sperm acrosome reaction is a prerequisite for oocyte fertilization, and to date the mechanisms regulating this event are still unclear. Recent studies have demonstrated that human follicular fluid is able to induce an influx of extracellular calcium and acrosome reaction in capacitated spermatozoa. More recently these effects have been attributed to progesterone. The results of our study demonstrated that progesterone is able to trigger the capacitation, acrosome reaction, and fertilizability in human spermatozoa through a calcium mediated mechanism, suggesting a clinical use of this steroid in the treatment of spermatozoa for the different techniques of assisted fertilization.

Acrosome↗
PubMedDate not supplied

Possible significance of seminal zinc on human spermatozoa functions.

This study has been performed to investigate the possible role of seminal zinc in the regulation of human spermatozoa functions. Sperm cells from fertile men were washed and pooled, and in each cellular suspension we determined: a) spermatozoal uptake of zinc, b) effects of different albumin concentrations on cellular zinc content, c) effects of zinc and albumin on spermatozoal O2 consumption, d) effects of different zinc concentrations on albumin induced acrosome reaction. We observed that increases of extracellular zinc cause corresponding increases of spermatozoal zinc and that albumin exerts an important chelating effect, even at very low concentrations, on cellular zinc content. Zinc also possesses a reversible inhibitory effect on spermatozoa O2 consumption in a dose-related way, and albumin is able to reverse this effect. Albumin-induced acrosome reaction was also significantly reduced by addition of different zinc concentrations. Our findings reveal that zinc exerts an important influence on human spermatozoa functions and suggest that zinc may be involved in the mechanisms that maintain spermatozoa in the transitory quiescent state until penetration in the female reproductive tract.

Acrosome↗
PubMedDate not supplied

Sperm nuclear chromatin heterogeneity in infertile subjects.

Sperm chromatin heterogeneity has been evaluated in infertile males affected by different testicular diseases: 37 subjects had undergone orchidopexy in childhood (ex-cryptorchid), 50 were affected by idiopathic varicocele, 18 had a history of bilateral post-parotitis orchitis and 23 were "idiopathic infertiles". All subjects, except post-parotitis orchitic patients, exhibited significantly higher sperm chromatin heterogeneity than controls, with the highest incidence in ex-cryptorchid and in idiopathic infertiles. Ex-cryptorchid subjects also presented a significant positive linear correlation (p less than 0.001) between degree of sperm chromatin abnormality and percentage of morphological sperm alterations. Four monolateral ex-cryptorchid subjects showed a higher percentage of chromatin heterogeneity even when the cryptorchid testis had been removed during orchidopexy. In patients affected by varicocele, we also observed a significant correlation between chronological age and percentage of chromatin alterations. The results are discussed in relation to the pathogenesis of the disease concerned. Since sperm chromatin heterogeneity appears to be strongly involved in the development of infertility, we would suggest that it should be evaluated in routine diagnostic procedures of male infertility.

Adult↗