Oxytocin improves testicular blood flow without enhancing the steroidogenic activity in Baladi goats

Objective: To investigate the effects of a single oxytocin injection on plasma steroid concentrations, testicular blood flow measures (resistive and pulsatility indexes), and testicular echogenicity in Baladi goats. Methods: Twelve Baladi goat bucks were randomly allocated into 2 groups and received an intravenous injection of either 0.7 IU/kg oxytocin or normal saline 0.9%. Venous blood samples were collected, and testicular blood flow Doppler parameters (i.e, peak systolic velocity, end-diastolic velocity, time average maximum velocity, resistive index, and pulsatility index) were assessed for supratesticular arteries in the left and right testes immediately before (0), and at 5, 30, 60, and 120 min after injection. Results: Plasma concentrations of testosterone significantly decreased in the oxytocin group at 60 min post-treatment compared to the control group, whereas plasma concentrations of estradiol-17 β were not affected (P>0.05). Both resistive index and pulsatility index declined in the oxytocin group at 60 min posttreatment compared to the control group (P<0.05). Testicular pixel intensity increased at 30 min post-treatment in the oxytocin group compared to the control group (P<0.05). Conclusions: Oxytocin treatment significantly increases testicular blood flow and decreases plasma testosterone concentrations in male Baladi goats.