| Abstract: | Described in this paper is a method to characterize capacitation of bull spermatozoa. Involved is the action of 0.005 per cent of hyamine 2389 on selected motile cells at 37 degrees C for 30 minutes to detect the number of spermatozoa capable of acrosomal reaction. The latter amount results from the percentual difference between acrosome-free spermatozoa prior to hyamine action and those after hyamine action. Acrosome-free spermatozoa can be easily identified by means of simple staining under optical light microscopy. The value thus obtained is related to the amount of spermatozoa in progressively motile in the unselected original suspension and is called "Percentage Acrosome Reaction Induction" (% ARI). The ARI capacitation-specific acts: Only small amounts of acrosome-free spermatozoa are recordable among incapacitated spermatozoa or from spermatozoa incubated in the presence of decapacitation factors (1.9 or 2.3 per cent, respectively). On the other hand, clearly increased values of 17.6 ot 26.1 per cent are obtainable from treatments with capacitation effect (high ionic strength or addition of heparin). The method is claimed to be suitable for adequate choice of conditions for improved capacitation and in vitro fertilization as well as for elucidation of specific individual differences in capacitation. |
