1
|
Spontaneous Ejaculation: A Focused Review for the Clinicians. Sex Med Rev 2020; 9:406-422. [PMID: 33262094 DOI: 10.1016/j.sxmr.2020.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/25/2020] [Accepted: 11/01/2020] [Indexed: 01/23/2023]
Abstract
INTRODUCTION The process of ejaculation has important meanings not only for its association with orgasm but also for the timing to ejaculate in the context of sexual activity. Spontaneous (involuntary) ejaculation (SE) without any sexual stimulation is a distressing symptom. Our understanding of SE is limited. Unfortunately, many physicians are not aware of these cases. OBJECTIVES The objective of this study is to describe the etiopathogenesis, clinical features, diagnosis, and treatment options for SE. METHODS We searched the literature for publications on "SE," "spontaneous emission" or "involuntary ejaculation," and factors influencing SE in the PUBMED/MEDLINE, Scopus, Cochrane Library, EMBASE, PsycINFO, ProQuest, Academic Search Complete database, Google Scholar, and CINAHL databases from inception to August 2020. RESULTS The literature search yielded 36 relevant publications reporting on 43 patients with SE. Attempts to explain the cause of pathologic SE have included 4 etiological groups (spinal cord lesions, psychological causes, rabies, and drug-induced). The underlying mechanisms responsible for induction of SE may include increased adrenergic activity, overactivity in dopaminergic system, decreased serotonergic activity, damage of descending inhibitory pathway, or penile hyperexcitability. SE may occur in the absence of an identifiable trigger or may be triggered by non-sexual circumstances (micturition, defecation, glans touch, anxiety, panic attack, or school examinations). Treatment options include psychoanalytic treatment, paroxetine, citalopram, sertraline, silodosin, and anxiolytics. In drug-induced SE, dose reduction and drug withdrawal with or without switching to another drug may relief SE. CONCLUSIONS SE is one of the least reported ejaculatory dysfunction. The key feature shared in common by these men is SE without any sexual thoughts or fantasies, may be triggered by non-sexual contexts, rarely associated with orgasm or erection. Treatment by psychoanalytic treatment and pharmacotherapy may be helpful. Further research might explore the definite underlying mechanisms. Abdel-Hamid IA, Ali OI. Spontaneous Ejaculation: A Focused Review for the Clinicians. Sex Med Rev 2021;9:406-422.
Collapse
|
2
|
Hernández-Aguilar ME, Serrano MK, Pérez F, Aranda-Abreu GE, Sanchez V, Mateos A, Manzo J, Rojas-Durán F, Cruz-Gomez Y, Herrera-Covarrubias D. Quantification of neural and hormonal receptors at the prostate of long-term sexual behaving male rats after lesion of pelvic and hypogastric nerves. Physiol Behav 2020; 222:112915. [PMID: 32389668 DOI: 10.1016/j.physbeh.2020.112915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 11/26/2022]
Abstract
Prostate function is regulated by androgens and a neural control via the pelvic and hypogastric nerves. As such, this sexual gland contains receptors for acetylcholine and noradrenaline, although it is unknown whether the expression of these receptors is affected by sexual behavior and even less by denervation of the gland. Thus, the purpose of this work was to evaluate the effect of repeated sexual behavior on the expression of noradrenaline, acetylcholine, and androgen receptors at the prostate, and how they are affected by denervation. To achieve this, we used sexually experienced males denervated at the pelvic or hypogastric nerves, or both. The messenger (mRNA) and protein for androgen, noradrenergic, and cholinergic receptors were evaluated. The weight of the gland and the levels of serum testosterone were also measured. We found that: (1) sexual behavior was not affected by denervation; (2) blood testosterone levels increased due to sexual behavior but such increase is prevented by denervation; (3) the weight of the ventral prostate increased with sexual behavior but was not affected by denervation; (4) AR messenger levels increased with sexual behavior but were not altered by denervation; (5) the messenger for noradrenergic and cholinergic receptors decreased after denervation, and those for muscarinic receptors increased, and (6) only AR protein decreased after denervation of both nerves, while those for other receptors remained unchanged. In summary, we show that the three receptors have different regulatory mechanisms, and that only androgen receptors are regulated by both autonomic systems.
Collapse
Affiliation(s)
- María Elena Hernández-Aguilar
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México; Doctorado en Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México; Centro Tlaxcala en Biología de la Conducta, Universidad Autónoma deTlaxcala, Tlaxcala, México.
| | - María Karina Serrano
- Doctorado en Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México.
| | - Fabiola Pérez
- Doctorado en Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México.
| | | | - Viridiana Sanchez
- Doctorado en Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México.
| | - Alejandro Mateos
- Doctorado en Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México.
| | - Jorge Manzo
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México.
| | - Fausto Rojas-Durán
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Veracruz, México.
| | - Yolanda Cruz-Gomez
- Centro Tlaxcala en Biología de la Conducta, Universidad Autónoma deTlaxcala, Tlaxcala, México.
| | | |
Collapse
|
3
|
Abstract
The 1CH (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use) Guideline for Detection of Toxicity to Reproduction for Medicinal Products, adopted at the Second ICH Conference in Orlando, FL, U.S.A., emphasized the need for research into the suitability of various methods for the detection of effects on fertility in males. The current project was undertaken to compare the efficiency of methods by evaluating reports in the open literature. The results of the examination of 117 substances or substance classes support the view that histopathology and organ weight analysis provide the best general-purpose means of detecting substances with the potential to affect male fertility. Examinations at up to 4 weeks of treatment appear to be as effective as examinations conducted at later times. Mating with females for detection of effects unrelated to interference with sperm production appears to provide an optimal combination because adding other methodologies does not materially improve the detection rate. As to the timing of the mating trial, a 2-week premating period is as efficient as mating at 4 weeks and apparently more efficient than mating after prolonged premating treatment.
Collapse
Affiliation(s)
- Beate Ulbrich
- Federal Institute for Drugs and Medical Devices, Berlin, Germany; Huntingdon Research Centre, Huntingdon, Cambridgeshire, England
| | - Anthony K. Palmer
- Federal Institute for Drugs and Medical Devices, Berlin, Germany; Huntingdon Research Centre, Huntingdon, Cambridgeshire, England
| |
Collapse
|
4
|
Diaz R, Garcia LI, Locia J, Silva M, Rodriguez S, Perez CA, Aranda-Abreu GE, Manzo J, Toledo R, Hernandez ME. Histological modifications of the rat prostate following transection of somatic and autonomic nerves. AN ACAD BRAS CIENC 2010; 82:397-404. [PMID: 20563420 DOI: 10.1590/s0001-37652010000200015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 01/25/2010] [Indexed: 11/21/2022] Open
Abstract
It is known that hormones influence significantly the prostate tissue. However, we reported that mating induces an increase in androgen receptors, revealing a neural influence on the gland. These data suggested that somatic afferents (scrotal and genitofemoral nerves) and autonomic efferents (pelvic and hypogastric nerves) could regulate the structure of the prostate. Here we assessed the role of these nerves in maintaining the histology of the gland. Hence, afferent or efferent nerves of male rats were transected. Then, the ventral and dorsolateral regions of the prostate were processed for histology. Results showed that afferent transection affects prostate histology. The alveoli area decreased and increased in the ventral and dorsolateral prostate, respectively. The epithelial cell height increased in both regions. Efferent denervation produced dramatic changes in the prostate gland. The tissue lost its configuration, and the epithelium became scattered and almost vanished. Thus, afferent nerves are responsible for spinal processes pertaining to the trophic control of the prostate, activating its autonomic innervation. Hence, our data imply that innervation seems to be synergic with hormones for the healthy maintenance of the prostate. Thus, it is suggested that some prostate pathologies could be due to the failure of the autonomic neural pathways regulating the gland.
Collapse
|
5
|
Delgado-Gonzalez E, Aceves C, Anguiano B. Postejaculatory increase of prostatic triiodothyronine (T3) depends on sympathetic innervation in the rat. Biol Reprod 2010; 84:118-23. [PMID: 20811014 DOI: 10.1095/biolreprod.110.086116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Thyronines are essential for the development of the male reproductive system, including the prostate gland. Metabolically active 3,5,3' triiodothyronine (T(3)) is generated mainly by the extrathyroidal, enzymatic 5'deiodination of the prohormone thyroxine (T(4)), which is catalyzed by deiodinases type 1 (D1) and type 2 (D2). Prostate D1 activity is highly expressed during puberty and declines with age, but continuous, long-term sexual activity prevents this reduction. The aims of this study were to characterize the changes in prostatic D1 activity in response to consecutive ejaculations and to determine whether sympathetic input participates in the local T(3) generation (D1 activity). D1 activity was analyzed in prostates of sexually experienced, 4-mo-old male rats after one to five ejaculations. D1 activity, T(3) concentrations, and the T(3)-dependent gene ornithine decarboxylase (Odc) were measured after the fourth ejaculation in prostates of intact, sham, and sympathectomized (Smpx, hypogastric nerve) rats. D1 activity was evaluated by the radio-iodine-release method; T(3) was measured by radioimmunoassay and Odc expression by real-time PCR. Data showed a gradual increase of prostate D1 activity in response to consecutive ejaculations. The highest activity was found after the fourth ejaculation, and it decreased after the fifth. The increase of prostate D1 activity after ejaculation was blocked in Smpx males as compared to intact or sham animals. The changes in D1 activity correlate with prostatic T(3) concentrations and Odc expression. Circulating levels of T(3) were not affected by consecutive ejaculations or by Smpx. These findings indicate that the postejaculatory increase in prostatic generation of T(3) depends on sympathetic input.
Collapse
Affiliation(s)
- Evangelina Delgado-Gonzalez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autonoma de Mexico, Queretaro, Mexico
| | | | | |
Collapse
|
6
|
Sun X, Xu C, Leclerc P, Benoît G, Giuliano F, Droupy S. Spinal neurons involved in the control of the seminal vesicles: A transsynaptic labeling study using pseudorabies virus in rats. Neuroscience 2009; 158:786-97. [DOI: 10.1016/j.neuroscience.2008.10.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2008] [Revised: 10/02/2008] [Accepted: 10/06/2008] [Indexed: 10/21/2022]
|
7
|
|
8
|
Yaïci ED, Rampin O, Tang Y, Calas A, Jestin A, Leclerc P, Benoit G, Giuliano F. Catecholaminergic projections onto spinal neurons destined to the pelvis including the penis in rat. Int J Impot Res 2002; 14:151-66. [PMID: 12058242 DOI: 10.1038/sj.ijir.3900809] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2001] [Accepted: 07/26/2001] [Indexed: 11/09/2022]
Abstract
In rats, the spinal cord contains proerectile autonomic motoneurons destined to the penile tissue and its vasculature, and somatic motoneurons destined to the perineal striated muscles. It receives dense catecholaminergic projections issued from the medulla and pons. In adult male rats, we evidenced the catecholaminergic innervation of spinal neurons controlling lower urogenital tissues and regulating penile erection. We combined retrograde tracing techniques and immunohistochemistry against synthetic enzymes of noradrenaline and adrenaline. Both sympathetic and parasympathetic preganglionic neurons, labeled from the major pelvic ganglion or from the corpus cavernosum, were apposed by catecholaminergic immunoreactive fibers. Motoneurons, retrogradely labeled from the striated muscles, were also apposed by catecholaminergic immunoreactive fibers. Synapses between these motoneurons and fibers were suggested by confocal microscopy and confirmed by electron microscopy in some cases. The results reinforce the hypothesis of a catecholaminergic control of autonomic and somatic motoneurons regulating penile erection at the spinal level.
Collapse
Affiliation(s)
- E D Yaïci
- Groupe de Recherche en Urologie, UPRES EA 1602, Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre, France
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
This chapter will give personal accounts of the neural basis of male rat sexual behavior from two somewhat different perspectives, one tilted towards neuroanatomy (K.L.), and one tilted towards monoaminergic pharmacology (S.A.). Both perspectives were strongly influenced by the Zeitgeist, the former imperceptibly merging into the latter as relations between the neural substrate for monoaminergic neurotransmission was elucidated.
Collapse
Affiliation(s)
- K Larsson
- Department of Psychology, University of Göteborg, Sweden.
| | | |
Collapse
|
10
|
Kempinas WD, Suarez JD, Roberts NL, Strader LF, Ferrell J, Goldman JM, Narotsky MG, Perreault SD, Evenson DP, Ricker DD, Klinefelter GR. Fertility of rat epididymal sperm after chemically and surgically induced sympathectomy. Biol Reprod 1998; 59:897-904. [PMID: 9746741 DOI: 10.1095/biolreprod59.4.897] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Guanethidine, a chemical that selectively blocks sympathetic noradrenergic neurons, was used to investigate the role of sympathetic innervation in the fertility of rat epididymal sperm, using both natural mating and in utero insemination protocols. This animal model correlates, at least in part, with spinal cord injury (SCI) in men. Adult male rats were treated daily by i.p. injections, for 21 or 42 days, with 0 or 6.25 mg/kg guanethidine. To compare the effects of guanethidine-induced sympathectomy with those following surgically induced sympathectomy, the inferior mesenteric ganglion and the proximal hypogastric nerves were removed in another group of rats. Both chemically and surgically induced sympathectomy increased the weight of the epididymis and seminal vesicles/coagulating glands as well as the number and the transit time of cauda epididymal sperm. Neither serum testosterone levels nor LH was affected by treatment with guanethidine. Using natural mating, no litters were produced by guanethidine-treated rats. Chemically denervated rats failed to produce copulatory plugs or ejaculate into the uterus. However, distal cauda epididymal sperm from chemically or surgically denervated rats displayed normal fertilization ability (80%) using in utero inseminations. In addition, the sperm of denervated rats did not show abnormal sperm chromatin structure using an assay that detects DNA damage. We conclude that sympathectomy delays the transit of sperm through the cauda epididymidis and produces ejaculatory dysfunction but does not compromise sperm quality in the distal cauda epididymidis. Moreover, these data provide compelling evidence that there is no association between the prolonged transit time of sperm within the epididymis, i.e., pre-ejaculatory sperm aging, and the fertility of those sperm, which has important implications for artificial insemination using sperm from men with SCI.
Collapse
Affiliation(s)
- W D Kempinas
- Departamento de Morfologia, Instituto de Biociências - UNESP, Botucatu, SP, Brazil.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Clark JT. Sexual function in altered physiological states: comparison of effects of hypertension, diabetes, hyperprolactinemia, and others to "normal" aging in male rats. Neurosci Biobehav Rev 1995; 19:279-302. [PMID: 7630583 DOI: 10.1016/0149-7634(94)00058-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In this review, we examine the changes in sexual function that accompany deviations from "normal" physiological states. We propose that the changes one observes in many altered physiological states should not be viewed in isolation. We describe our paradigms for assessing sexual function, and proceed to evaluate how sexual function changes with hormonal deprivation and aging, in rat models for hypertension, in severe hyperprolactinemia, in streptozotocin-induced diabetes, after chronic alcohol intake, after chronic morphine administration, and after exposure to the heavy metal, cadmium. We will provide evidence for the involvement of adrenergic transmitters and two neuropeptides, neuropeptide Y and somatostatin, in the neuroendocrine regulation of sexual behavior. Finally, we compare and contrast the changes observed relative to the changes seen in "normal" aging in rats. The sequence of age-related changes in sexual function is distinct. The first change observed is a decrement in ex copula erectile reflexes. Next are decreases in ejaculatory threshold, followed shortly by increases in initiation and reinitiation of copulation after ejaculation. This is followed by a decrement in the number of males copulating to ejaculation. Finally, there is a failure to initiate the copulatory process. This sequelae is relatively common, being evident after castration, with hyperprolactinemia, and after exposure to cadmium. The data available for sexual function in hypertension is incomplete and modified by the etiology, but a suggestion for this sequelae is seen in SHR. In contrast, sexual dysfunction associated with chronic morphine administration appears to be due to an initial deficit in motivational aspects. Testosterone reverses sexual dysfunction associated with castration, but not with idiopathic sexual inactivity, nor with sexual dysfunction associated with aging, diabetes, or chronic morphine administration. Comparing sexual function in rat models for hypertension, diabetes and chronic ethanol leads to the conclusion that increases in blood pressure, like decreases in testosterone, cannot be the primary causal factor for sexual dysfunction. Age, hormonal history of the subject, and the age at castration influence changes in sexual function. Age-related sexual dysfunction appears to be contributed to by changes in adrenergic-neuropeptidergic, to include sympathetic, systems. Site-specific administration of NPY induces alterations in parameters of copulatory behavior which mimic those seen in aging and the retention of ejaculatory behavior with aging is associated with site-selective attenuation (or reversal) of age-associated changes in NPY content. Yohimbine enhances copulatory activity in castrated and aging rats, and attenuates or reverses the antisexual effects of clonidine, epinephrine and somatostatin.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- J T Clark
- Department of Physiology, Meharry Medical College, Nashville, TN 37208, USA
| |
Collapse
|
12
|
Kempinas WG, Petenusci SO, Rosa e Silva AA, Favaretto AL, Carvalho TL. The hypophyseal-testicular axis and sex accessory glands following chemical sympathectomy with guanethidine of pre-pubertal to mature rats. Andrologia 1995; 27:121-5. [PMID: 7598229 DOI: 10.1111/j.1439-0272.1995.tb01081.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Selective chemical sympathectomy of the internal sex organs of prepubertal to mature male Wistar rats was performed by chronic treatment with low doses of guanethidine. Plasma testosterone and luteinizing hormone and the intratesticular level of testosterone were determined. The weight and fructose content of seminal vesicle and ventral prostate were also investigated. The results showed that sympathetic innervation is related to the control of the hypophyseal-testicular axis as well as to the growth and potential secretory activity of the male sex accessory glands.
Collapse
Affiliation(s)
- W G Kempinas
- Institute of Biosciences, UNESP, Botucatu, USP, Ribeirão Preto, Brasil
| | | | | | | | | |
Collapse
|
13
|
|
14
|
Shir Y, Seltzer Z. Effects of sympathectomy in a model of causalgiform pain produced by partial sciatic nerve injury in rats. Pain 1991; 45:309-320. [PMID: 1876441 DOI: 10.1016/0304-3959(91)90056-4] [Citation(s) in RCA: 152] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In a previous report we presented a novel behavioral model of neuropathic pain disorders, produced in rat by a unilateral ligation of about half of the sciatic nerve. The model is characterized by rapid onset of behaviors suggesting spontaneous pain and disordered responses to non-noxious and noxious stimuli. These include reduced withdrawal thresholds to repetitive touch in the partially deafferented skin ('touched-evoked hyperesthesia'), touch-evoked allodynia, reduced withdrawal thresholds to noxious thermal stimuli and exaggerated responses to noxious heat and mechanical stimuli ('thermal hyperalgesia'). Some of these disorders are seen at mirror image sites on the hind limb opposite the lesion. These disorder start within hours after partial nerve injury, last many months and are very similar to causalgia in humans following partial nerve injury. Since sympathetic efferent activity is known to aggravate causalgia in humans and sympathectomy is known to relieve it, we studied the effect of changing sympathetic outflow in the rat model. Reversible sympathectomy was carried out using guanethidine injected intraperitoneally in 3 experiments, each at a different time in relation to the partial nerve injury. We found that: (1) sympathectomy performed several months postoperatively alleviated the sensory disorders bilaterally; (2) sympathectomy prior to nerve injury partially prevented the appearance of thermal hyperalgesia but did not affect hyperesthesia to repetitive touch; and (3) sympathectomy at the time of nerve injury aggravated the sensory disorders during the first few days. As maintenance and production of the sensory disorders in this animal model depended on sympathetic nervous outflow, we conclude that the rats were suffering from a syndrome analogous to sympathetically maintained causalgia in man.
Collapse
Affiliation(s)
- Yoram Shir
- Department of Anesthesiology and Pain Clinic, Hadassah University Hospital, JerusalemIsrael Physiology Branch, Faculty of Dental Medicine, Hebrew University of Jerusalem Israel
| | | |
Collapse
|
15
|
Seltzer Z, Shir Y. Sympathetically-maintained causalgiform disorders in a model for neuropathic pain: a review. J Basic Clin Physiol Pharmacol 1991; 2:17-61. [PMID: 1786259 DOI: 10.1515/jbcpp.1991.2.1-2.17] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Partial nerve injury is the main cause of sympathetically maintained causalgiform pain disorders in humans. We present here an animal model of this condition, produced in rats by a unilateral ligation of about half of the sciatic nerve. Starting hours after the operation and for several months thereafter, the rats developed signs of spontaneous pain, touch-evoked allodynia and hyperesthesia, and mechanical and thermal hyperalgesia in the partially denervated as well as the intact contralateral foot. These disorders were maintained by the sympathetic outflow and disappeared following postoperative sympathectomy. In neonatally capsaicinated rats we found that touch-evoked allodynia and hyperesthesia were mediated by A-fibers whereas thermal hyperalgesia was mediated by C-fibers. These disorders were not due to receptor sensitization of remaining afferent fibers by prostaglandins. We found strain differences and genetic inheritance of these causalgiform disorders which were correlated with the expression of autotomy to hind-paw denervation.
Collapse
Affiliation(s)
- Z Seltzer
- Physiology Branch, Faculty of Dental Medicine, Hebrew University of Jerusalem, Israel
| | | |
Collapse
|
16
|
Schnur SL, Smith ER, Lee RL, Mas M, Davidson JM. A component analysis of the effects of DPAT on male rat sexual behavior. Physiol Behav 1989; 45:897-901. [PMID: 2528754 DOI: 10.1016/0031-9384(89)90212-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Male rat sexual behavior was examined in a variety of tests following a single acute IP injection of the serotonin1A (5-HT1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (DPAT). The objective was to determine the effects of 5-HT1A receptor stimulation on the components of sexual behavior (arousal/motivation, erection and ejaculation) using this prototypical 5-HT1A ligand. In the ex copula genital reflex test, DPAT dramatically inhibited ejaculation and the display of penile erections. When examined in the mating behavior test, DPAT caused a significant reduction in intromission frequency (IF), ejaculation latency (EL), intercopulatory intervals (ICI) and postejaculatory interval (PEI). The decrease in IF and EL indicated a lowering of the behavioral-ejaculatory threshold, while the reduction in ICI and PEI indicated a stimulation of two aspects of sexual arousal. Further tests, however, revealed complexities. Using the mounting test (with genital anesthesia) as an assessment of sexual arousal, no effect of DPAT was found. Collection and examination of the coagulated ejaculates resulting from mating (copulatory plugs) provided evidence of an impairment in ejaculation, as a result of DPAT treatment. The data suggests that 5-HT1A receptor stimulation lowers the behavioral-ejaculatory threshold despite inhibition of ejaculation in and ex copula; as well as stimulating specific aspects of sexual arousal. It remains to be determined whether the effects on arousal were either due to nonselectivity as currently believed or because 5-HT1A receptor stimulation affects alpha 2-adrenoceptor activity by some as yet undefined mechanism; and as a result modulates sexual arousal.
Collapse
Affiliation(s)
- S L Schnur
- Department of Physiology, Stanford University, School of Medicine, CA 94305-5070
| | | | | | | | | |
Collapse
|
17
|
Smith ER, Lee RL, Schnur SL, Davidson JM. Alpha 2-adrenoceptor antagonists and male sexual behavior: II. Erectile and ejaculatory reflexes. Physiol Behav 1987; 41:15-9. [PMID: 2891150 DOI: 10.1016/0031-9384(87)90124-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Three alpha 2-adrenoceptor antagonists, yohimbine, idazoxan, and imiloxan, all shown to have stimulatory effects on sexual arousal/motivation, were studied to identify their possible effects on the other two major components of male copulatory behavior: erection and ejaculation. Genital reflex ex copula tests were used in order to assess these two responses without the confounding factors of mating behavior. Dose ranges were yohimbine: 0.25-4.0 mg/kg; idazoxan: 1.0-8.0 mg/kg; and imiloxan: 12.5-50.0 mg/kg. Lower doses of two of the drugs significantly enhanced the frequency of erections, while the third (yohimbine) showed a strong trend in that direction. At higher doses, all three alpha 2-antagonists produced significant reductions in the number of rats showing penile reflexes, including both erections and ejaculations. In those rats which did show penile reflexes, higher doses of yohimbine (4.0 mg/kg) inhibited the frequency of erections, while the higher dose of idazoxan showed a trend towards such inhibition. Thus, profound, largely inhibitory effects of these agents were demonstrated at dose ranges which have been shown to enhance sexual arousal. These data indicate that within the nervous system alpha 2-adrenoceptor antagonists can modulate erectile and ejaculatory mechanisms quite independently from effects on arousal/motivation.
Collapse
Affiliation(s)
- E R Smith
- Department of Physiology, Stanford University, CA 94305-5070
| | | | | | | |
Collapse
|