Vibratory Stimulation of Ejaculation Yields Increased Motile Spermatozoa, Compared with Electroejaculation, in Squirrel Monkeys (Saimiri boliviensis).
Semen sample collection in squirrel monkeys has traditionally relied on electroejaculation (EE) via the rectum; how- ever, the yield is low when anesthesia is used. An alternative method has been advocated for men with spinal cord injury that relies on penile vibratory afferent stimulation. Vibratory stimulation (VS) physiologically coordinates emission and ejaculation without requiring anesthesia; this procedure was investigated in squirrel monkeys. During the breeding season, 10 donor males were evenly allotted to two groups; one received VS, and the other received EE. Three days later, treatments were reversed. For VS, a clinical unit was adapted to hold a 1.8-ml microcentrifuge tube as an artificial vagina. Unanesthetized, manually restrained animals were positioned in ventral recumbency. Vibratory stimulation consisted of a I-mm amplitude, 75-Hz stimulation for 1 min, rest for 1 min, then continued stimulation at 1.8-mm amplitude, 90 Hz for 1 min. For EE, animals were anesthetized by administration of Telazol(3.5 mg/kg of body weight, IM) and stimulated by EE via the rectum, using a 5- to 7.5-V, 60-Hz sine wave for 1 minute of 1 sec on/ I sec off and a probe with two longitudinal electrodes and a temperature monitor. Stimulation was repeated after 1 minute s rest. Semen samples were diluted, incubated, centrifuged, and evaluated for spermatozoal count and motility. Nine of 10 monkeys responded to VS with semen samples, all of which contained spermatozoa. Mean motility was 79.8% and total mean motile spermatozoa yield was 26.1 (range, 0.4 to 110) million. By use of EE, all monkeys produced semen samples, but only 6 samples contained spermatozoa, with mean motility of 70% and low yield of 0.534 (range, 0.038 to 2.2) million motile spermatozoa. In conclusion, penile VS was superior with regard to quantity of motile spermatozoa obtained. Additionally, no anesthesia was necessary for this relatively benign procedure.
Yeoman
Richard R.
RR
Department of Obstetrics/Gynecology, University of South Alabama, Mobile, AL 36688.
Ricker
Robert B.
RB
Williams
Lawrence E.
LE
Sonksen
Jens
J
Abee
Christian R.
CR