Objectives: The behaviour of head and tail sperm membrane subjected to different vitality tests was evaluated, searching for possible correlations with sperm motility.
Study design: On fresh semen from seven rabbits we performed: the Eosin Exclusion Test (EET) and, with different incubation times (T(0), T(5), T(30)), a Hypoosmotic Swelling Test (HOS-test) and a combined Hypoosmotic and Eosin Test (HE-test). Kinetic parameters were determined by using the CASA system CELL-TRAK. Statistical analysis was performed by one way ANOVA and Pearson's correlation coefficient.
Results: The HOS-test revealed significant differences between percentages of curled spermatozoa at T(0) (67.86+/-4.28) versus T(5) (72.86+/-3.28) and versus T(30) (75.14+/-6.5). Among four types of spermatozoa obtained with the HE-test, percentage of Type 1 sperm (HOS+/Eosine) at T(0) (32.3%+/-6.65), was lower than motile sperm (66.86%+/-9.72) but positively correlated.
Conclusions: The HE-test is a rapid instrument for predicting sperm motility, selecting spermatozoa with a high degree of membrane resistance both in the tail and the head compartment.