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Transactions of the American Clinical... 2019The field of sexual medicine, in reference to the science of the sexual response and the clinical management of sexual dysfunctions, has evolved remarkably in the last... (Review)
Review
The field of sexual medicine, in reference to the science of the sexual response and the clinical management of sexual dysfunctions, has evolved remarkably in the last 25 years. Erection biology has been central in driving this progress and is measured considerably by the discovery, study, and clinical translation of a simple gaseous molecule, nitric oxide, which is operative in the penis. Nitric oxide functions extraordinarily as a neurotransmitter and molecular signal transducer. It is now well understood to be the principal molecular mediator of penile erection and to be a critical element involved in dysregulatory mechanisms of erection disorders ranging from erectile dysfunction to priapism. It is most familiarly associated with the scientific development of oral medications for treating erectile dysfunction, which has modernized the clinical management of this condition.
Topics: Erectile Dysfunction; Humans; Male; Nitric Oxide; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type III; Penile Erection; Phosphodiesterase 5 Inhibitors; Sildenafil Citrate
PubMed: 31516164
DOI: No ID Found -
Sensors (Basel, Switzerland) Nov 2022Quantifiable erectile dysfunction (ED) diagnosis involves the monitoring of rigidity and tumescence of the penile shaft during nocturnal penile tumescence (NPT). In this...
Quantifiable erectile dysfunction (ED) diagnosis involves the monitoring of rigidity and tumescence of the penile shaft during nocturnal penile tumescence (NPT). In this work, we introduce Erectile Dysfunction SENsor (EDSEN), a home-based wearable device for quantitative penile health monitoring based on stretchable microtubular sensing technology. Two types of sensors, the T- and R-sensors, are developed to effectively measure penile tumescence and rigidity, respectively. Conical models mimicking penile shaft were fabricated with polydimethylsiloxane (PDMS) material, using different base to curing agent ratios to replicate the different hardness properties of a penile shaft. A theoretical buckling force chart for the different penile models is generated to determine sufficiency criteria for sexual intercourse. An average erect penile length and circumference requires at least a Young's modulus of 179 kPa for optimal buckling force required for satisfactory sexual intercourse. The conical penile models were evaluated using EDSEN. Our results verified that the circumference of a penile shaft can be accurately measured by T-sensor and rigidity using the R-sensor. EDSEN provides a private and quantitative method to detect ED within the comfortable confines of the user's home.
Topics: Male; Humans; Erectile Dysfunction; Penile Erection; Wearable Electronic Devices; Hardness; Elastic Modulus
PubMed: 36502045
DOI: 10.3390/s22239344 -
Biomolecules Dec 2021Nitric oxide (NO), the neuromodulator/neurotransmitter formed from l-arginine by neuronal, endothelial and inducible NO synthases, is involved in numerous functions... (Review)
Review
Nitric oxide (NO), the neuromodulator/neurotransmitter formed from l-arginine by neuronal, endothelial and inducible NO synthases, is involved in numerous functions across the body, from the control of arterial blood pressure to penile erection, and at central level from energy homeostasis regulation to memory, learning and sexual behavior. The aim of this work is to review earlier studies showing that NO plays a role in erectile function and sexual behavior in the hypothalamus and its paraventricular nucleus and the medial preoptic area, and integrate these findings with those of recent studies on this matter. This revisitation shows that NO influences erectile function and sexual behavior in males and females by acting not only in the paraventricular nucleus and medial preoptic area but also in extrahypothalamic brain areas, often with different mechanisms. Most importantly, since these areas are strictly interconnected with the paraventricular nucleus and medial preoptic area, send to and receive neural projections from the spinal cord, in which sexual communication between brain and genital apparatus takes place, this review reveals that central NO participates in concert with neurotransmitters/neuropeptides to a neural circuit controlling both the consummatory (penile erection, copulation, lordosis) and appetitive components (sexual motivation, arousal, reward) of sexual behavior.
Topics: Animals; Arginine; Central Nervous System; Female; Humans; Male; Nitric Oxide; Nitric Oxide Synthase; Penile Erection; Sexual Behavior
PubMed: 34944510
DOI: 10.3390/biom11121866 -
British Journal of Pharmacology Mar 2015The ability to get and keep an erection is important to men for several reasons and the inability is known as erectile dysfunction (ED). ED has started to be accepted as... (Review)
Review
The ability to get and keep an erection is important to men for several reasons and the inability is known as erectile dysfunction (ED). ED has started to be accepted as an early indicator of systemic endothelial dysfunction and subsequently of cardiovascular diseases. The role of NO in endothelial relaxation and erectile function is well accepted. The discovery of NO as a small signalling gasotransmitter led to the investigation of the role of other endogenously derived gases, carbon monoxide (CO) and hydrogen sulphide (H2 S) in physiological and pathophysiological conditions. The role of NO and CO in sexual function and dysfunction has been investigated more extensively and, recently, the involvement of H2 S in erectile function has also been confirmed. In this review, we focus on the role of these three sister gasotransmitters in the physiology, pharmacology and pathophysiology of sexual function in man, specifically erectile function. We have also reviewed the role of soluble guanylyl cyclase/cGMP pathway as a common target of these gasotransmitters. Several studies have proposed alternative therapies targeting different mechanisms in addition to PDE-5 inhibition for ED treatment, since some patients do not respond to these drugs. This review highlights complementary and possible coordinated roles for these mediators and treatments targeting these gasotransmitters in erectile function/ED.
Topics: Animals; Carbon Monoxide; Cyclic GMP; Drug Design; Erectile Dysfunction; Guanylate Cyclase; Humans; Hydrogen Sulfide; Male; Molecular Targeted Therapy; Nitric Oxide; Penile Erection; Receptors, Cytoplasmic and Nuclear; Signal Transduction; Soluble Guanylyl Cyclase
PubMed: 24661203
DOI: 10.1111/bph.12700 -
Ultrasound in Obstetrics & Gynecology :... Oct 2001
Topics: Female; Humans; Male; Penile Erection; Penis; Pregnancy; Ultrasonography, Prenatal
PubMed: 11779005
DOI: 10.1046/j.0960-7692.2001.00477.x -
TheScientificWorldJournal Jun 2004
Review
Topics: Erectile Dysfunction; Humans; Male; Muscle, Smooth, Vascular; Penile Erection; Penis
PubMed: 15349538
DOI: 10.1100/tsw.2004.58 -
Scientific Reports Jun 2021Erectile dysfunction (ED) is mostly due to the lack of blood flow into the penis. In the past 20 years, near-infrared spectroscopy (NIRS) was used in measuring the... (Clinical Trial)
Clinical Trial
Erectile dysfunction (ED) is mostly due to the lack of blood flow into the penis. In the past 20 years, near-infrared spectroscopy (NIRS) was used in measuring the concentrations and temporal dynamics of different hemoglobin types. However, the dynamics of the light absorption (photoplethysmography; PPG) have not been applied to survey penile hemodynamics and erection quality. This paper compared the use of photoplethysmography (PPG) to study vascular ED with standard penile Doppler ultrasonography. Men diagnosed with vascular ED for at least 6 months and nominated for penile ultrasonography were included. PPG signals were collected during the ultrasound examination. All beat-to-beat PPG waveforms were aligned with the peak and averaged to one representative template waveform for feature analysis, including amplitude differences (APD) index, reflection time index (RTI), augmentation index (AI), and perfusion index (PI). An inverse correlation was found between end-erection amplitude and both erection hardness score (EHS) and resistive index (RI). APD index and EHS as well as the international index of erectile function-5 (IIEF) and RI were positively correlated. RTI and AI were inversely correlated to IIEF and RI. PI was positively correlated to RI. PPG may therefore be useful as a noninvasive, convenient, technique for sexual function evaluation.
Topics: Aged; Hemodynamics; Humans; Male; Middle Aged; Penile Erection; Penis; Photoplethysmography
PubMed: 34103629
DOI: 10.1038/s41598-021-91582-9 -
CMAJ : Canadian Medical Association... Apr 2004Dramatic advances in the management of erectile dysfunction have occurred over the past decade. Oral therapy with vasoactive agents has emerged as first-line treatment... (Review)
Review
Dramatic advances in the management of erectile dysfunction have occurred over the past decade. Oral therapy with vasoactive agents has emerged as first-line treatment and has transformed both the manner in which the public views erectile dysfunction and the way health care providers deliver care. Whereas an extensive investigation was previously common in the management of erectile dysfunction, recent treatment guidelines promote a more minimalist, goal-oriented approach. In this article, we review the physiology of erection, and the pathophysiology, diagnosis and clinical management of erectile dysfunction. We also present the existing evidence for the efficacy of 3 phosphodiesterase inhibitors, the most widely used class of agents for erectile dysfunction.
Topics: Erectile Dysfunction; Humans; Imidazoles; Male; Penile Erection; Phosphodiesterase Inhibitors; Physical Examination; Piperazines; Purines; Sildenafil Citrate; Sulfones; Triazines; Vardenafil Dihydrochloride
PubMed: 15111479
DOI: 10.1503/cmaj.1020049 -
International Journal of Radiation... Mar 2010The dose, volume, and clinical outcome data for penile bulb are reviewed for patients treated with external-beam radiotherapy. Most, but not all, studies find an... (Meta-Analysis)
Meta-Analysis Review
The dose, volume, and clinical outcome data for penile bulb are reviewed for patients treated with external-beam radiotherapy. Most, but not all, studies find an association between impotence and dosimetric parameters (e.g., threshold doses) and clinical factors (e.g., age, comorbid diseases). According to the data available, it is prudent to keep the mean dose to 95% of the penile bulb volume to <50 Gy. It may also be prudent to limit the D70 and D90 to 70 Gy and 50 Gy, respectively, but coverage of the planning target volume should not be compromised. It is acknowledged that the penile bulb may not be the critical component of the erectile apparatus, but it seems to be a surrogate for yet to be determined structure(s) critical for erectile function for at least some techniques.
Topics: Erectile Dysfunction; Humans; Magnetic Resonance Imaging; Male; Models, Biological; Penile Erection; Penis; Radiation Injuries; Radiotherapy Dosage; Tomography, X-Ray Computed
PubMed: 20171507
DOI: 10.1016/j.ijrobp.2009.04.094 -
Asian Journal of Andrology 2019Although elevated prolactin levels have been shown to inhibit penile erection, the relationship between prolactin and erection of the penile tip or base has not been...
Although elevated prolactin levels have been shown to inhibit penile erection, the relationship between prolactin and erection of the penile tip or base has not been extensively researched. We therefore investigated the prolactin's effects on erection of the penile tip and base, with a cross-sectional study of 135 patients with erectile dysfunction, based on scores of ≤21 on the International Index of Erectile Function-5. All patients were tested for nocturnal penile tumescence, blood pressure, serum glucose, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, luteinizing hormone, follicle-stimulating hormone, prolactin, estradiol, testosterone, and progesterone. Univariate and multivariate analyses were used to assess the associations between prolactin levels and erection at the penile tip and base. We found no obvious relationship between erection time at penile tip and prolactin levels, but observed a negative correlation between base erection time and prolactin level (hazard ratio: -2.68; 95% confidence interval [CI]: -5.13--0.22). With increasing prolactin concentration, multivariate analysis showed obvious reduction in base erection time among patients with normal Rigiscan results (hazard ratio: -3.10; 95% CI: -7.96-1.77; P < 0.05). Our data indicate that prolactin inhibits penile erection, particularly at the penile base. In addition, when the effective erection time of the penile base lasts longer than 10 min, prolactin has a more obvious inhibitory effect on penile base erection.
Topics: Adult; Cross-Sectional Studies; Erectile Dysfunction; Humans; Male; Penile Erection; Prolactin; Time Factors
PubMed: 31044754
DOI: 10.4103/aja.aja_22_19