Determination of Plasma Membrane Characteristics: RESULTS(3)

RESULTS(3)

Experiment 4. Activation Energy for Boar Spermatozoa Glycerol and Water Permeability in the Presence of Extender

Glycerol permeability and its associated Lp was determined in the presence of Modena extender at 22°C, 8°C, and 0°C; the results can be seen in Table 5. Hydraulic conductivity was 0.156 ± 0.031, 0.0860 ± 0.013, and 0.0604 ± 0.009 |xm/min/atm at 22°C, 8°C, and 0°C, respectively. Solute permeability was determined to be 0.681 ± 0.711, 0.473 ± 0.566, and 0.293 ± 0.663 X 10~3 cm/min, at 22°C, 8°C, and 0°C, respectively. The reflection coefficients were estimated to be 0.865 ± 0.025, 0.825 ± 0.046, and 0.840 ± 0.050 at 22°C, 8°C, and 0°C, respectively. Activation energy for hydraulic conductivity was estimated to be 6.88 Kcal/mol and 5.95 Kcal/mol for glycerol permeability (Fig. 3). asthma inhalers

TABLE 5. Boar spermatozoa permeability characteristics in the presence of Modena extender (mean ± SEM).

Temperature(°C) (fim/min/atm) pglycerol(10~3 cm/min) а (n)a
22 0.156 ± 0.031 0.681 ± 0.711 0.865 ± 0.025 3
8 0.0860 ± 0.013 0.473 ± 0.566 0.825 ± 0.046 3
0 0.0604 ± 0.009 0.293 ± 0.663 0.840 ± 0.050 3
Ea (Kcal/mol) 6.88 5.95

Experiment 5: Simulation of Cryoprotectant Addition and Removal

Computer simulations of the addition and removal of glycerol (Fig. 4) and EG (Fig. 5) show the resulting relative cell volume change over time at room temperature. The results indicate that glycerol causes more cell volume excursion during its addition and removal than does EG, at room temperature.

Experiment 6. Simulation of Intracellular Water Volume Flux during Cooling and Warming

Computer simulations of intracellular water volume excursions experienced during the cryopreservation process can be seen in Figure 6. Data are shown as relative cell water volume as a function of temperature in degrees centigrade until 0°C is reached, at which point it becomes a function of time in seconds. The results indicate that both glycerol and EG could be used effectively to cryopreserve boar spermatozoa when cooling rates of 10°C/min and 100°C/min, respectively, are used, with a warming rate of 1200°C/min. However, EG is ineffective for boar spermatozoa cryopreservation due to the increased cell water volume excursion when cooling rates exceed 1000°C/min with a similar warming rate. The potential for intracellular ice formation remained low (< 5%) for each CPA across all three cooling rates.

Fig4Determination of plasma membrane
FIG. 4. Computer simulation for the addition (A) and dilution (B) of 1 M glycerol to boar spermatozoa at 22°C. Addition procedures considered a 1:1 dilution of cell suspension to CPA. Addition rates, resulting in different cell responses, varied between 0 and 9 min. Dilution procedures considered a 9:1 dilution of isosmotic media to CPA/cell suspension. Dilution rates varied between 0 and 9 min. The horizontal bar refers to the osmotic limits within which 80% sperm motility could be maintained.

Fig5Determination of plasma membrane
FIG. 5. Computer simulation for the addition (A) and dilution (B) of 1 M EG to boar spermatozoa at 22°C. Addition procedures considered a 1: 1 dilution of cell suspension to CPA. Addition rates, resulting in different cell responses, varied between 0 and 9 min. Dilution procedures considered a 9:1 dilution of isosmotic media to CPA/cell suspension. Dilution rates varied between 0 and 9 min. The horizontal bar refers to the osmotic limits within which 80% sperm motility could be maintained.

This entry was posted in Spermatozoa and tagged Boar, Cryopreservation, Plasma Membrane, Spermatozoa.