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Freezing Medium (freezing + medium)

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Medical Sciences	100%

Selected Abstracts

Modification of standard freezing media to limit capacitation and maximise motility of frozen-thawed equine spermatozoa

AUSTRALIAN VETERINARY JOURNAL, Issue 12 2003
MA SCHEMBRI
Objective To investigate cryopreservation-induced capacitation-like changes in equine spermatozoa frozen in three different media using chlortetracycline (CTC) fluorescence staining analysis. Procedure Semen collected from three stallions was diluted in one of three centrifugation media and, after centrifugation and removal of supernatant, extended in corresponding freezing media containing additional egg yolk, glycerol, lactose and Equex paste. The semen was frozen in 5 mL straws and the spermatozoa assessed for motility and membrane quality after thawing. Results Following centrifugation, spermatozoa diluted with modified Kenney's Centrifugation Medium (MKCM) displayed a higher percentage of (normal) F pattern (94.3%) compared with spermatozoa in Kenney's Centrifugation Medium (KCM) (84.9%) and Glucose-EDTA Centrifugation Medium (GECM) (85.2%). Conversely, the percentage of spermatozoa displaying the (capacitated) B pattern was higher in the KCM (14.1%) and GECM (13.8%) than in the MKCM (5.0%). Following freezing-thawing, there were lower percentages of spermatozoa displaying the AR (acrosome reacted) pattern in modified Kenney's Freezing Medium (MKFM) (45.6%) compared with Kenney's Freezing Medium (KFM) (61.4%) and lactose-EDTA Freezing Medium (LEFM) (61.1%). There was a correspondingly higher percentage of spermatozoa displaying the B pattern in MKFM (52.3%) compared with KFM (37.9%) and LEFM (38.6%). There was no significant difference between the freezing media in the percentage of spermatozoa displaying the F pattern. The percentage of progressively motile spermatozoa was also influenced by the type of freezing medium (P< 0.001). Post-thaw percentages of progressively motile spermatozoa, frozen in MKFM, KFM, and LEFM, were 31.4, 25.8 and 23.3%, respectively. Conclusion MKFM was the preferred medium for cryopreservation of equine spermatozoa due to its superior protection against changes in motility and membrane quality compared with the other freezing media studied. [source]

Effect of pentoxifylline on motility and membrane integrity of cryopreserved human spermatozoa

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2002
P. Stanic
The purpose of this study was to examine the effects of pentoxifylline used before and after semen cryopreservation,thawing on sperm motility and membrane integrity. Twenty-four semen samples were split into four equal aliquots. Aliquots were incubated at 37 °C for 30 min, followed by cryopreservation with TEST-yolk freezing medium using slow programmable freezing protocol. After 2 weeks the sperm samples were thawed, washed twice in Quinn's Sperm Washing Medium (modified HTF with 5.0 mg/mL Human Albumin) and incubated at 37 °C for 30 min. Aliquots were treated by adding 3 mmol/L pentoxifylline to: (1) fresh sperm samples during incubation period prior to cryopreservation, (2) sperm samples as a supplement to the cryoprotectant prior to cryopreservation, and (3) thawed sperm samples during incubation period. One aliquot received no treatment (control group). The addition of 3 mmol/L pentoxifylline to fresh semen during incubation period prior to cryopreservation significantly decreased progressive and total motility compared with controls. However, the addition of 3 mmol/L pentoxifylline to cryopreserved semen after thawing significantly increased progressive and total motility compared with controls. After post-thaw, no differences in motion characteristics between sperm samples treated by adding 3 mmol/L pentoxifylline as a supplement to the cryoprotectant and control groups were observed. Post-thaw hypoosmotic swelling (HOS) test scores did not improve with the addition of pentoxifylline compared with the control group. It is concluded that pentoxifylline enhanced post-thaw motility of cryopreserved human spermatozoa when added after thawing. No improvement was found by freezing sperm with pentoxifylline. [source]

Freezing equine semen: the effect of combinations of semen extenders and glycerol on post-thaw motility

AUSTRALIAN VETERINARY JOURNAL, Issue 7 2009
J Scherzer
Objective We evaluated combinations of two commercial semen extenders and three concentrations of glycerol to determine the combination that yielded the highest post-thaw sperm motility. Design A randomised 2 × 3 block design was used. Procedure Semen was collected from four stallions (6 collections per stallion). The sample was diluted with either a dried skim-milk glucose extender (EZ Mixin Original Formula) or a chemically defined, milk-free diluent (INRA 96), and each was used in combination with 2%, 3% or 4% glycerol in standard commercial freezing medium. Sperm motility was assessed by microscopy in fresh and post-thaw semen. Results There was a significant difference between the two extenders in the motility of spermatozoa after cryopreservation (48.9% for INRA 96; 38.6% for EZ Mixin OF; P < 0.0001). Glycerol at 4% in freezing medium yielded the highest post-thaw motility, significantly better than 2% (P < 0.05). Three of four stallions had significantly higher post-thaw motility using INRA 96 relative to EZ Mixin OF (P < 0.01), and two of four stallions had significantly higher post-thaw motility using 4% glycerol (P < 0.05). The combination of INRA 96 and 4% glycerol in freezing medium gave the highest average post-thaw motility of 51.5%. Conclusion In this study, INRA 96 combined with 4% glycerol yielded an average recovery of progressively motile sperm consistently above the 35% target. [source]