Brief note about plasma catecholamines kinetics and submaximal exercise in untrained standardbreds.

Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977) and noradrenaline (r = 0.976) during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788). This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.

Membrane integrity evaluation in rabbit spermatozoa.

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.