Ejaculation

Abstract: Objective To study the ejaculatory mechanisms in men using a dynamic endorectal ultrasonographical approach. Subjects and methods Seven recordings were made of a young healthy volunteer during ejaculation, scanning the longitudinal plane from the bladder neck to the bulbous urethra. Results The study demonstrated the existence of a preejaculatory phase characterized by a notable decrease in echogenicity of the inner prostate gland, due to the contraction of the pre-prostatic sphincter 13-2 5 s before ejaculation. Several stages were recorded including an ejaculatory stage with an initial prostatic emission phase lasting 2–20 s and a posterior emission phase through the ejaculatory ducts lasting 3–14 s, with a seminal stoppage of 3–8 s. and finally a urethro-vesical reflux of a minimal fraction of the ejaculate over 5–9 s. The bladder neck and inner gland returned to their resting configuration between 10 and 90 s after ejaculation. Conclusions Endorectal ultrasonographical imaging during ejaculation, a recently developed diagnostic procedure, may provide a new approach to ejaculation-related problems.

Abstract: This paper reviews our experience with rectal probe electroejaculation (RPE) which is part of a larger effort to determine the correlates of successful ejaculation and fertility in SCI men. RPE is performed in the outpatient clinic using specially designed rectal probes. Over the past 18 months, we have attempted RPE on 38 occasions in 12 subjects (eight paraplegics and four quadriplegics) with an age range of 23-38 years and 0.5-18 years since onset of injury. Anterograde ejaculation occurred in nine subjects with improvement in percent motility and total live sperm count on repeated stimulations in five subjects. Significant retrograde ejaculation occurred in one person and sperm acceptable for artificial insemination (AI) was obtained from four subjects. The major side effects were mild dysreflexia (three subjects) and disruption of a normal bowel program (one subject). We conclude that RPE is a safe, relatively brief outpatient procedure and, with repeated stimulations, has a good potential for producing sperm acceptable for AI in selected patients.

Abstract: Ejaculation is the final stage of coitus in mammalian male and is mandatory for natural procreation. Two synchronized phases, emission and expulsion, form the ejaculatory response and involve specific organs and anatomical structures. The peripheral events leading to ejaculation are commanded by autonomic (sympathetic and parasympathetic) and somatic divisions of the nervous system. The autonomic and somatic motor efferents originate in spinal nuclei located in thoracolumbar and lumbosacral segments. Co-ordinated activation of autonomic and somatic spinal nuclei is orchestrated by a group of lumbar spinal interneurons defined as the spinal generator of ejaculation. The generator of ejaculation together with the autonomic and somatic spinal nuclei constitutes a spinal network that is under the strong influence of stimulating or inhibiting genital sensory and supraspinal inputs. A brain circuitry dedicated to ejaculation has been delineated that is part of a more global network controlling other aspects of the sexual response. This circuitry includes discrete neuronal populations distributed in all divisions of the brain. The corollary to the expanded CNS network is the variety of neurotransmitter systems participating in the ejaculatory process. Among them, serotonin neurotransmission plays a key role and its targeting led to the development of the first registered pharmacological treatment of premature ejaculation in human beings. Critical gaps remain in the understanding of neurophysiopharmacology of ejaculation and management of ejaculatory disorders in human beings needs improvement. Because the ejaculatory response in laboratory animals and in human beings shares many similarities, the use of animal models will certainly provide further advances in the field.