Penile vibratory stimulation yields increased spermatozoa and accessory gland production compared with rectal electroejaculation in a neurologically intact primate (Saimiri boliviensis)

Assisted reproductive techniques require an efficient semen collection proc edure in cases of ejaculatory dysfunction, Anejaculation may be of psychoge nic or neurogenic origin but can be overcome with stimulatory techniques. P enile vibratory stimulation (PVS) therapy for anejaculation has recently em erged as an alternative to rectal probe electroejaculation (RPE) and more i nvasive testicular procedures. Comparison of the stimulatory procedures in neurologically intact subjects is not ethically possible due to the discomf ort involved with electroejaculation, and comparison in spinal cord injured men may be compromised due to the intricate effects of chronic denervation on semen quality. We have previously shown the efficicacy of PVS in a non- human primate, the squirrel monkey. A cross-over study design comparing sem en collected by PVS and RPE was employed during the breeding season in whic h 15 donor males were divided into two groups. One group received PVS and t he other RPE, then, three days later, treatments were reversed. Twelve of 1 5 animals responded to PVS (80%), all with spermatozoa in the ejaculate. Me an volume (436 +/- 90 mu l), motility (80.6 +/- 4.3%), and total spermatozo a (32.8 +/- 10.2x10(6)) were significantly higher than in the semen after R PE, RPE resulted in ejaculation in all 15 animals with a semen volume of 20 5 +/- 25 mu l, but fewer samples contained spermatozoa (9/15) resulting in a low total count (0.5 +/- 0.3x10(6)). The motility was reduced in those sa mples with spermatozoa (n = 9; 44.1 +/- 11.4%), Additionally, accessory gla nd activity was measured via the seminal vesicle and prostrate markers, fru ctose and citric acid, respectively. The PVS specimens had significantly mo re fructose (2.9 +/- 0.7 mg/ejaculate) and citric acid (0.46 +/- 0.14 mg/ej aculate) compared to RPE collected specimens (1.2 +/- 0.3 mg/ejaculate and 0.24 +/- 0.04 mg/ejaculate, respectively). In conclusion, PVS produces a mu ch greater sperm yield and increased accessory gland secretion compared to RPE in our neurologically intact squirrel monkey model.