Hexose-specificity of hexokinase and ADP-dependence of pyruvate kinase play important roles in the control of monosaccharide utilization in freshly diluted boar spermatozoa.

Incubation of boar sperm from fresh ejaculates in a minimal medium with 10 mM glucose induced a fast and intense activation of glycolysis, as indicated by the observed increases in the intracellular levels of glucose 6-phosphate (G 6-P) and ATP and the rate of formation of extracellular L-lactate. The effect of glucose was much more intense than that induced by fructose, sorbitol, and mannose. The greater utilization of glucose was related to a much greater sensitivity to hexokinase when compared with the other monosaccharides.

Study of the polyol pathway in the porcine epididymis.

Concentrations of D-glucose, D-fructose and D-sorbitol were quantified in porcine epididymal fluid by spectrofluorimetric assays and aldose reductase (AR) and sorbitol dehydrogenase (SDH) were located immunohistochemically in the epididymal epithelium. Glucose and fructose concentrations were low (<1 mM) and decreased in the cauda whereas sorbitol concentration (4-7 mM) was rather uniform along the duct. AR was luminally located on microvilli in the caput and corpus with less presence distally and was present in the lumen.

Concentrations of carnitine, glutamate and myo-inositol in epididymal fluid and spermatozoa from boars.

This study examines the concentrations of carnitine, glutamate and myo-inositol in fluid and spermatozoa from six epididymal regions. Samples were taken from six post-pubertal boars, and the sperm concentration, the protein concentration in epididymal fluid and the concentrations of carnitine, myo-inositol and glutamate in the epididymal fluid and spermatozoa were analysed. In epididymal fluid the concentration of myo-inositol decreased in a proximo-distal direction, whereas intraluminal concentrations of L-carnitine and L-glutamate increased distally.

Development of a protocol for multiple staining with fluorochromes to assess the functional status of boar spermatozoa.

The aim of this study was to design a simple and reliable method for the simultaneous evaluation of the nucleus, the acrosome, and the mitochondrial sheath of boar spermatozoa. Sperm samples coming from healthy and sexually mature Pietrain boars were incubated with two nuclear fluorochromes--bis-benzamide specific for viable cells, and propidium iodide specific for nonviable cells--the fluorochrome Mitotracker Green FM specific for functional mitochondria, and the lectin Trypsin inhibitor from Soybean (SBTI) conjugated with the fluorochrome Alexa Fluor 488 specific for proacrosin. The results obtained from assessing the functional status of the spermatozoa using fluorochromes were compared with the conventional sperm parameters of sperm vitality using the eosin exclusion test (EE test), and sperm motility and morphology using the computer-assisted semen analyzer SCA 2002Producció.

Proliferation and apoptosis of spermatogonia in postpuberal boar (Sus domesticus) testes with spontaneous unilateral and bilateral abdominal cryptorchidism.

Cryptorchidism is a frequent male sexual disorder in mammals, which affects the histology of the tunica propria, interstitial tissue, blood vessels, seminiferous epithelium and testis functioning. In this paper, proliferation and apoptosis were examined in the seminiferous epithelium of both testes from unaffected boars and from boars suffering unilateral and bilateral cryptorchidism. In germ cells, proliferation was studied using the immunohistochemical PCNA technique, and apoptosis was analysed by in situ TUNEL labelling.

Effects of a high semen-collection frequency on the quality of sperm from ejaculates and from six epididymal regions in boars.

This study examines the effect of semen-collection rhythm on the sperm maturation process in boar epididymis. Three post-pubertal boars were submitted to a high semen-collection frequency (stressed boars) during 4 days, and three males were kept as a control group (control boars). Semen samples coming from six epididymal regions and from the ejaculate of each male were evaluated for sperm concentration, sperm vitality, sperm motility and sperm morphology.