Incidences of sperm head membrane, acrosomal and postacrosomal damage in dog spermatozoa Frozen-thawed using two cryopreservation methods (Andersen and CLONE), were estimated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray microanalysis. Neither the proportion of spermatozoa with intact plasma membranes after freezing-thawing, estimated by SEM, nor the proportion with swollen acrosomes? as estimated by TEM, differed significantly between methods, the proportions in both cases being larger than 65%. The proportion of spermatozoa with disrupted acrosomal membranes after freezing-thawing with either method was low, around 5%, as estimated using both SEM and TEM. However, freezing and thawing were followed by significant changes in the elemental composition in the postacrosomal region of the sperm heads. Both cryopreservation methods caused a significant decrease in intracellular concentrations of potassium. The Andersen method resulted in a significant increase in Ca-concentrations and a significant decrease in Cl-concentrations. The CLONE method caused a significant decrease in sulphur concentrations. Although whelping rates are generally high in practice using intrauterine insemination when using spermatozoa cryopreserved with either of the evaluated methods, the acrosomal changes seen in a high proportion of the spermatozoa and changes in the elemental composition of their heads suggest that cryopreservation-induced modifications might impair their longevity and fertilizing ability. Improvement in these aspects might lead to higher whelping rates also after vaginal insemination or when timing of the insemination is not optimal.
Canine sperm head damage after freezing-thawing: Ultrastructural evaluation and content of selected elements
ROTA, ALESSANDRA;
1998-01-01
Abstract
Incidences of sperm head membrane, acrosomal and postacrosomal damage in dog spermatozoa Frozen-thawed using two cryopreservation methods (Andersen and CLONE), were estimated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray microanalysis. Neither the proportion of spermatozoa with intact plasma membranes after freezing-thawing, estimated by SEM, nor the proportion with swollen acrosomes? as estimated by TEM, differed significantly between methods, the proportions in both cases being larger than 65%. The proportion of spermatozoa with disrupted acrosomal membranes after freezing-thawing with either method was low, around 5%, as estimated using both SEM and TEM. However, freezing and thawing were followed by significant changes in the elemental composition in the postacrosomal region of the sperm heads. Both cryopreservation methods caused a significant decrease in intracellular concentrations of potassium. The Andersen method resulted in a significant increase in Ca-concentrations and a significant decrease in Cl-concentrations. The CLONE method caused a significant decrease in sulphur concentrations. Although whelping rates are generally high in practice using intrauterine insemination when using spermatozoa cryopreserved with either of the evaluated methods, the acrosomal changes seen in a high proportion of the spermatozoa and changes in the elemental composition of their heads suggest that cryopreservation-induced modifications might impair their longevity and fertilizing ability. Improvement in these aspects might lead to higher whelping rates also after vaginal insemination or when timing of the insemination is not optimal.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
