Alterations in the penile artery blood flow hemodynamics and hormonal profile in jacks (Equus asinus) after a single administration of human chorionic gonadotropin (hCG)

The penis of the donkey is a musclocavernous type as the erection of the penis is dependent on the blood flow within the cavernous tissue inside the penis,This current study aimed for the first time to determine the effect of human chorionic gonadotropin (hCG) injection on penile artery blood flow hemodynamics and erection process after carefully studying the anatomical architecture of the penile blood supply. This study was conducted on 23 donkeys as 3 Male cadavers were used for anatomical findings and the other 20 live jacks were subdivided into two equal groups (Group I [treated jacks; n = 10] and Group II [control males; n = 10]). The arterial supply of the penis of the horse is oriented by external pudendal, internal pudendal and obturator arteries. The penile artery Doppler indices were declined (P < 0.05) in the hCG group after a single injection of hCG by 2,4 and reached the lowest level at 6 h. The penile blood flow volume reached the highest level 6 h after injection. The levels of both nitric oxide (NO), estradiol (E2), and follicle-stimulating hormone (FSH) were elevated, reaching the peak point after 6 h. of injection for E2 and NO and 4 h for FSH. There was a positive correlation between penile blood flow and both NO and E2 (NO with r = 0.66; P = 0.01, and E2 with r = 0.69; P = 0.01). In conclusion, the single administration of hCG improves the penile artery vascularity and hormonal levels at 6 h. post-injection, which positively affects penile function and the erection process in jacks (Equus asinus).