Seminal fluids are known to have a variety of effects on rival sperm, but in externally fertilizing species it is still unclear what effects seminal fluid can induce under sperm competition. We recorded sperm activity from natural ejaculates (including own seminal fluid) of an external fertilizer, the Arctic charr (Salvelinus alpinus), after activation either in water (the natural medium for mi...

Two experiments were designed to examine the effects of crude seminal plasma (CSP) exposure ofejaculated and epididymal spermatozoa before freezing. Experiment 1, two consecutive ejaculates werecollected (n=4) within 5 min, the second one was carried out in a tube containing Fiser extender (coatedspermatozoa); by centrifugation, seminal plasma was removed from coated ejaculates. The pellets wer...

objective: cigarette is a rich source of oxidants and reactive nitrogen species. nitric oxide (no) in high concentration has deleterious effects on human sperm function. antioxidant defense system in seminal plasma protects spermatozoa from the attack of reactive oxygen metabolites. the purpose of this study was to determine the correlation between cigarette smoking with the no levels and the t...

conclusions these results suggest that serum cholesterol, phospholipids and triacylglycerols have no effect on the levels of cholesterol, phospholipids and triacylglycerols of spermatozoa and seminal plasma. our findings suggest that sperm lipid content is regulated locally within the male reproductive tract. patients and methods cholesterol, phospholipids and triacylglycerols in sperm cells, s...

Abstract—Male factor infertility due to endocrine disturbances such as abnormalities in prolactin levels are encountered in a significant proportion. This case control study was carried out to determine the effects of prolactin on the male reproductive tract, using 200 male white rats. The rats were maintained as the control group (G1), hypoprolactinaemic group (G2), 3 hyperprolactinaemic group...

INTRODUCTION The lipid composition of the sperm membrane has a significant effect on the functional characteristics of spermatozoa. PATIENTS AND METHODS In the present study, fatty acid composition of spermatozoa and seminal plasma levels of free 15-F(2t)-Isoprostane and catalase were assayed in men with normozoospermia, asthenozoospermia, asthenoteratozoospermia, and oligoasthenoteratozoospe...

Abstract—Male factor infertility due to endocrine disturbances such as abnormalities in prolactin levels are encountered in a significant proportion. This case control study was carried out to determine the effects of prolactin on the male reproductive tract, using 200 male white rats. The rats were maintained as the control group (G1), hypoprolactinaemic group (G2), 3 hyperprolactinaemic group...

The major predecessor to Ringen's and my own efforts to measure democratic quality in terms of the purpose of democracy is Robert Dahl's seminal book Polyarchy (1971). Measuring the quality of democracy requires two prior judgments: (1) making sure that, in terms of institutional characteristics, a country is sufficiently democratic, and that, as a minimum, it has universal suffrage, and (2) th...