Determination of Plasma Membrane Characteristics: RESULTS(1)

RESULTS(1)Experiment 1: Osmotic Tolerance Limits for Boar Spermatozoa

Figure 2 demonstrates the relative percentage of motile cells as a function of osmolality. Motility is evaluated in anisosmotic conditions, and 1 and 5 min after return to isosmolality. The results indicate that there was no significant effect of treatment (cells in anisosmotic conditions vs. returned to isosmotic conditions; p = 0.943) on motility. Table 3 summarizes the percentages of volume excursions cells can tolerate during swelling and shrinking while still maintaining 90%, 80%, and 70% motility, respectively.

Fig2Determination of plasma membrane
FIG. 2. Normalized percentage of motility (mean ± SEM, n = 3) of boar spermatozoa that were abruptly exposed to different anisosmotic conditions (circles) and returned to isosmotic conditions after 1 min (squares) and after 5 min (triangles) at room temperature (A) or in the presence of Modena extender at room temperature (B).

Experiment 2: Activation Energy for Boar Spermatozoa Solute and Water Permeability

Changes in cell volume, measured over time, were fitted to compute PCPA and Lp at 22°C, 8°C, and 0°C; results can be seen in Table 4. Hydraulic conductivity (L„) was estimated to be 0.120 ± 0.016 (mean ± SEM), 0.138 ± 0.006, and 0.204 ± 0.021 ixm/min/atm in the presence of DMSO, glycerol, and EG, respectively, at 22°C. Cryoprotectant permeability (Pcpa) was determined to be 0.930 ± 0.118, 0.481 ± 0.045, and 1.98 ± 0.106 X 10 3 cm/min for DMSO, glycerol, and EG, respectively, at 22°C. The reflection coefficients were estimated to be 0.724 ± 0.077, 0.896 ± 0.011, and 0.763 ± 0.034 for DMSO and water, glycerol and water, and EG and water, respectively. Subsequent experiments were performed at 8°C and 0°C to determine the activation energy for glycerol, EG, water and glycerol, and water and EG permeability. Hydraulic conductivity (Lp) was estimated to be 0.072 ± 0.005 and 0.052 ± 0.006 (im/min/atm in the presence of glycerol at 8°C and 0°C, respectively; and 0.092 ± 0.005 and 0.041 ± 0.003 |xm/min/atm in the presence of EG at 8°C and 0°C, respectively. buy antibiotics online

TABLE 3. Percentage of boar spermatozoa motility is given as a function of the upper osmotic tolerance limit (UTL) and lower osmotic tolerance limit (LTL), given in percentage of isosmotic cell volume, in the presence and absence of Modena extender.

% Motility AbsencextenUTL :e of derLTL Pre!exUTL ;ence of tenderLTL
In anisosmotic conditions
90 1.01 0.99 1.01 0.99
80 1.01 0.98 1.07 0.98
70 1.02 0.97 1.11 0.97
After return to isosmotic
conditions for 1 min
90 1.00 0.99 1.01 0.99
80 1.01 0.98 1.05 0.98
70 1.02 0.97 1.10 0.97
After return to isosmotic
conditions for 5 min
90 1.00 0.99 1.01 0.99
80 1.01 0.98 1.05 0.98
70 1.01 0.97 1.09 0.97

TABLE 4. Boar spermatozoa permeability characteristics (mean ± SEM).

Solute К(H.m/min/atm) (10″’ PРЛcm/min) <7 (n)*
Glycerol
22°C 0.138 ± 0.006» 0.481 ± 0.045» 0.896 -t- 0.011-‘ 3
8°C 0.072 ± 0.005b 0.316 ± 0.290b 0.852 -t- 0.028» 3
0°C 0.052 ± 0.006c 0.279 ± 0.280c 0.812 -t- 0.026» 3
Ethylene glycol 22°C 0.204 ± 0.02 1» 1.98 ± 0.106» 0.763 -t- 0.034» 3
8°C 0.092 ± 0.005b 1.08 ± 0.068b 0.719 -b 0.01 7» 3
0°C 0.041 ± 0.003′ 0.704 ± 0.033′ 0.561 0.041b 3
DMSO
22°C* Numl »~c Vail and with 0.120 ±oer of anin les with dil in column: 0.016nals usee ferent si s. 0.930iiperscri| ± 0.118 Dts are diffe 0.724 :rent (p < 0.077 0.05) wit 3hin CPA

 

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