Assessment of released acrosin activity as a measurement of the sperm acrosome reaction.
OBJECTIVE
To develop a method for assessing sperm function by measuring released acrosin activity during the acrosome reaction (AR).


METHODS
Human semen samples were obtained from 24 healthy donors with proven fertility after 3-7 days of sexual abstinence. After collection, samples were liquefied for 30 min at room temperature. Standard semen parameters were evaluated according to World Health Organization (WHO) criteria. Calcium ionophore A23187 and progesterone (P4) were used to stimulate the sperm to undergo AR. After treatment, sperm were incubated with the supravital dye Hoechst33258, fixed in a glutaraldehyde-phosphate-buffered saline solution, and the acrosomal status was determined by fluorescence microscopy with fluorescein isothiocyanate-labeled Pisum sativum agglutinin (FITC-PSA). The percentage of sperm undergoing AR (AR%) was compared to sperm acrosin activities as assessed by spectrocolorimetry. The correlation between AR% and acrosin activity was determined by statistical analysis.


RESULTS
The AR% and released acrosin activity were both markedly increased with A23187 and P4 stimulation. Sperm motility and viability were significantly higher after stimulation with P4 versus stimulation with A23187 (P < 0.001). There was a significant positive correlation between released acrosin activity and AR% determined by FITC-PSA staining (r=0.916, P < 0.001).


CONCLUSIONS
Spectrocolorimetric measurement of released acrosin activity might serve as a reasonable alternative method to evaluate AR.
Liu
Rui-Zhi
RZ
Department of Cell Biology, School of Basic Medical Sciences, Jilin University, 126 Xin-min Avenue, Changchun, China. lrz420@126.com
Na
Wan-Li
WL
Zhang
Hong-Guo
HG
Lin
Zhi-Yong
ZY
Xue
Bai-Gong
BG
Xu
Zong-Ge
ZG
D000176:Acrosin / Q000502:physiology*; D020101:Acrosome Reaction; D000328:Adult; D002681:China; D006801:Humans; D008297:Male; D011374:Progesterone / Q000494:pharmacology; D012661:Semen / Q000187:drug effects / Q000502:physiology*; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology*
D011374:Progesterone; D000176:Acrosin