Lysozyme activities and immunoglobulin concentrations in seminal plasma and spermatozoa of different teleost species and indications on its significance for sperm function

The occurrence of lysozyme and immunoglobulin (Ig) in semen of different teleost species (brown trout-Salmo trutta, perch-Perca fluviatilis, burbot-Lota lota) was studied In all investigated species lysozyme activities (1 13-1 45 U ml(-1)) and Ig concentrations (T-Ig. 1.11-1 61 mu g ml(-1), IgG [measured only in brown trout] 1 49 mu g ml(-1)) were detected in seminal plasma Ig was also found in spermatozoa (T-Ig 0 234-0 357 mu g/g protein, IgG 0 198 mu g ml(-1)) while spermatozoal lysozyme activities were low and fluctuating (0.093-0.164 U/g protein) In Salmo trutta lysozyme activities and immunoglobulin levels were compared between semen samples with high and low sperm motility as motility is an indicator for sperm fertility Lysozyme activities were higher in seminal plasma of samples with high motility than in those with low motility while seminal plasma and spermatozoal immunoglobulin concentrations (T-Ig, IgG) were increased in samples with low motility in comparison to samples with high motility. Seminal plasma and spermatozoal IgG concentrations and seminal plasma lysozyme activities showed significant correlations with the sperm motility rate and swimming velocity Moreover, lysozyme improved the viability of spermatozoa in in vitro experiments Possible physiological meanings of these results are discussed. (C) 2010 Elsevier Inc All rights reserved