Related Experiment Video
Updated: Aug 15, 2026
10:29
Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors
Published on: May 9, 2025
Why humans need type 5 phosphodiesterase inhibitors
1Scuola Normale Superiore and Istituto di Neuroscienze, CNR, Pisa, Italy. cellerino@in.cnr.it
International Journal of Andrology
|October 21, 2005
Summary
Erectile dysfunction (ED) is common, posing an evolutionary paradox. This study suggests ED acts as a sexually selected handicap, indicating lower fitness and hindering reproduction in males.
Area of Science:
- Evolutionary biology
- Human physiology
- Reproductive health
Background:
- Erectile dysfunction (ED) affects millions of males, presenting an evolutionary paradox due to its impact on reproduction.
- ED is linked to numerous diseases and stressors, serving as an indicator of overall health and a predictor of cardiovascular events.
- In nature, elaborate traits signal fitness but also act as handicaps, influencing mate selection.
Purpose of the Study:
- To explore the evolutionary paradox of widespread erectile dysfunction.
- To propose that erectile function in males is a sexually selected trait.
- To investigate the role of male sexual physiology as a condition-dependent handicap.
Main Methods:
- Review of epidemiological data on erectile dysfunction prevalence.
- Analysis of evolutionary principles regarding sexually selected traits and handicaps.
- Examination of the link between general health, environmental stressors, and erectile function.
Main Results:
- Erectile dysfunction is prevalent despite its reproductive consequences.
- Erectile function is sensitive to overall health, psychological, and environmental factors.
- Erection quality serves as an honest indicator of an individual's fitness.
Conclusions:
- The fragility of male sexual physiology may function as a sexually selected handicap.
- This handicap could limit reproduction in individuals with lower phenotypic quality.
- Understanding ED through an evolutionary lens offers insights into male reproductive health and mate selection.
Related Concept Videos
01:28Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors
Phosphodiesterase 5 (PDE5) inhibitors are potent enzymes that function to hydrolyze cyclic nucleotides to their corresponding 5' monophosphates. Their unique biochemical properties have been applied in treating Pulmonary Arterial Hypertension (PAH).
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...
01:18Trichomoniasis
Trichomonas vaginalis is a flagellated protozoan parasite and the causative agent of trichomoniasis, one of the most prevalent non-viral sexually transmitted infections in the United States. This extracellular parasite primarily colonizes the lower genitourinary tract in women—particularly the vagina—and in men, the urethra and prostate. Its structural and functional adaptations enable its survival, motility, and pathogenicity within the host environment.Structural Features and Host EntryT.
01:27Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:
01:23Dipeptidyl Peptidase 4 Inhibitors
Dipeptidyl peptidase 4 (DPP-4) is a serine protease widely distributed in the body. It's involved in the inactivation of GLP-1 and GIP hormones, which are crucial for insulin regulation. DPP-4 inhibitors, such as sitagliptin (Januvia), saxagliptin (Onglyza), linagliptin (Tradjenta), alogliptin (Nesina), and vildagliptin (Galvus), help increase the proportion of active GLP-1, enhancing insulin secretion. These inhibitors work by competitively binding to DPP-4. This binding causes a significant...
01:22Antiviral Nucleoside Inhibitors
Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),...
01:30Inhibitors of Viral Protein Synthesis
Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...