Untersuchungen zur Kapazitation und Hyperaktivierung equiner ...

Ergebnisse
stallions: at 2.5 versus 5 mM, resulting in VCL values ranging from 180 to 240 μm s -1
(figure 2).
Also, in vitro capacitation properties were different for sperm from these stallions.
First of all, ejaculates from different stallions exhibited different numbers of plasma
and acrosomal membrane intact cells (PI negative/FITC-PNA negative; closed black
squares). Furthermore, upon incubation in Tyrode A capacitation medium,
differences in the extent by which the number of membrane intact cells decreased
were seen, indicating differences amongst stallions in capability to undergo in vitro
capacitation. For example, stallion H1 (figure 3A) exhibits a decrease from 75% to
30% membrane intact cells, whereas stallion H5 (figure 3D) only decreases down to
45%.
4.2.4.3. Hyperactivation and in vitro capacitation properties in (non-)
capacitation medium supplemented with procaine
In figure 4, the average response of sperm incubated in Tyrode A capacitating
medium in compared with that of sperm incubated in Tyrode B control medium This
clearly illustrates that sperm undergo in vitro capacitation in Tyrode A capacitation
medium, but not in Tyrode B control medium, as is evident from the decrease in the
percentages of plasma and acrosomal membrane intact cells upon exposure to (non-
) capacitating conditions. Incubation in Tyrode B control medium only results in a
small decrease of only 5% in membrane intact cells during a 90 min incubation at 38
o C, whereas membranes become damaged for half of the sperm population upon
incubation in Tyrode A capacitation medium for 60 min. Incubation in Whittens A
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