Characterization of electrical and mechanical activities of rabbit uterus associated with the presence of capacitated and non-capacitated spermatozoa

Abstract

To investigate the effects capacitated spermatozoa may exert upon motility of the rabbit uterus, both contractility and electrical activity (frequency and intensity) were measured in 3 distinctive uterine segments of anaesthetized does: horn (UH), uterotubal junction (UTJ) and tube (UT) after 1) natural mating, 2) infusion of either seminal plasma or PBS, 3) infusion of either capacitated or non-capacitated spermatozoa. Basal values were: 17.1, 15.7, 16.4 g (contractility, P>0.05); 3.5, 3.5, 3.4 Hz (frequency, P>0.05); 0.49, 0.50, 0.57 μV (intensity, P>0.05) for UH, UTJ, UT, respectively. Seminal plasma caused an increase (P<0.05) in the UH contractility: 26.3 vs. 11.7 (natural mating) and 17.0 g (PBS); it also caused a decrease (P<0.05) in electrical intensity at the UTJ: 0.24 vs. 0.67 (natural mating) and 0.58 μV (PBS). The presence of either capacitated or non-capacitated spermatozoa caused no changes in contractility and electrical frequency in any of the uterine segments. However, there was a change in electrical intensity at UTJ (0.37 vs. 0.57 μV for non-capacitated and capacitated spermatozoa, respectively; P<0.05). There were also differences between segments by treatment: UTJ (0.37) vs. UT (0.59 μV) for non-capacitated; UH (0.46) vs. UT (0.71 μV) for capacitated spermatozoa (P<0.05). In conclusion, use of this experimental model showed that uterine electrical activity was slightly modified by the presence of capacitated spermatozoa.