Pattern C: sperm cells displaying fluorescence on the head that was greater in intensity at the acrosomal zone, thus they were considered as undergoing acrosomal reaction
. Table IV shows the percentage of intact sperm cells in fresh treatment and in those incubated with PVL.
Effects of progesterone, CatSper and Hv1 channel inhibitors on sperm acrosomal reaction
Acrosome reacted sperm (%) Subgroups (n-24) Control Progesterone (1 [micro]M) Ham's F10 7.1[+ or -]0.8 21.9[+ or -]1.7 p<0.001 (*) NNC (2 [micro]M) 7.1[+ or -]0.8 7.7[+ or -]0.8 p<0.001 (*) Zn (1 mM) 8.9[+ or -]0.7 9.8[+ or -]4.7 p<0.001 (*) NNC + Zn 8.4[+ or -]0.7 7[+ or -]0.
* Combination of Trolox and EDTA partly improved frozen-thawed sperm motility and reduced the spontaneous acrosomal reaction
This might reflect an increase of acrosomal volume, which could be related to the acrosomal reaction
Cholesterol and zinc usually stabilize sperm cell membrane and must be removed during capacitation to enable acrosomal reaction
and penetration of the ova.
In one study, the induction of the acrosomal reactions
using ionophore A23587 from 17.4 to 36.1% significantly increased the percentage of vacuole-free spermatozoa from 41.2% to 63.8% (P < 0.001) .
Intracellular calcium regulation in sperm capacitation and acrosomal reaction
Taurine prevents efflux of cholesterol from the sperm membrane and MDA production in diluents which indicates it prevents premature capacitation and acrosomal reaction
that act as an antioxidant.
Then spermatozoa adhere to the oocytes zona pellucida to induce the acrosomal reaction
, in which the fusion of the spermatozoal plasma membrane and the outer acrosomal membrane occurs to allow the acrosomal enzymes to be released.
At this point you might be wondering how binding of the sperm to the zona pellucida induces the morphologic changes associated with the acrosomal reaction
. The best way to understand this process is to view the interaction between the egg-binding protein and ZP3 as analogous to the interaction between a receptor and its hormone.
Induction of the acrosomal reaction
in mouse spermatozoa by the solution of pellucid zone from alpaca (Lama pacos L.)
The second, third and fourth steps of this process, respectively, are the acrosomal reaction
, the sperm cell and egg cell adhesion through the vitelline envelope, and the actual membrane contact between the two cells.