Membrane Integrity, Mitochondrial Activity, ATP Content, and Motility of the European Catfish (Silurus glanis) Testicular Spermatozoa after Freezing with Different Cryoprotectants

The extent of cellular damage was investigated after freeze–thawing of the European catfish testicular sperm with various cryoprotectants. The best protection was given by dimethylacetamide (10 and 15%) in a sucrose solution. Under these conditions, the percentage of cells with an intact membrane was high (90%), and the protection of the activity of the mitochondria was medium (47%). It was shown that the addition of dimethylacetamide largely increased the ATP content of the spermatozoa. It is suggested that this phenomenon is a decisive factor for the freezing resistance of European catfish testicular spermatozoa in the presence of dimethylacetamide (60% motility after thawing versus 90% before freezing).