Phosphodiesterase-5 Inhibitors as Therapeutics for Cardiovascular Diseases: A Brief Review.

Background: Three selective and most used inhibitors of PDE-5-sildenafil, vardenafil and tadalafil- have been successfully used for the treatment of erectile dysfunction. Erectile dysfunction and cardiovascular diseases might be considered as two dissimilar clinical signs of the identical systemic disease. PDE-5 inhibitors can through different models and mechanisms induce vasodilation, decrease apoptosis and cell proliferation, and they are widely present in various tissues that make them promising targets in a range of cardiovascular diseases. Methods: PubMed was explored to identify papers published from 1990-2019, presenting data for the most used PDE-5 inhibitors (sildenafil, tadalafil or vardenafil) in treatment of cardiovascular diseases. Results: This article analyses the therapeutic potentials of PDE-5 inhibitors in cardiovascular diseases and discusses mechanisms, possible risks and limitations. Comparable to earlier studies, newer studies suggest cardioprotective effects of PDE-5 inhibitors, which include different models and mechanisms and do not indicate an increased rate of significant cardiovascular adverse reactions. Dissimilarity in the pharmacokinetics and pharmacodynamics of PDE-5 inhibitors are significant to their risk- benefit profile and clinical use. Some of the studies suggesting infarct size reduction after PDE-5 inhibition described the especially close dose-effect relation, other studies dosage adaptation in drug- drug interactions. Conclusion: PDE-5 inhibitors indicate the encouraging useful effects by ischemia/reperfusion injury, myocar-dial infarction, cardiac hypertrophy, cardiomyopathy and systolic and diastolic congestive heart failure. Therefore, this and similar reviews can help for additional clinical targeting in the therapy of cardiovascular diseases.

Nandrolone decanoate and physical activity affect quadriceps in peripubertal rats.

Anabolic androgenic steroids (AASs) are synthetic analogs of testosterone often used by athletes to increase the skeletal muscle mass. Our goal was to examine the effects of physical activity and physical activity combined with supraphysiological doses of nandrolone on functional morphology of the quadriceps muscle. The study included 32 peripubertal Wistar rats, divided into 4 groups: control (T-N-), nandrolone (T-N+), physical activity (T+N-) and physical activity plus nandrolone (T+N+) groups. The T+N- and T+N+ group swam for 4 weeks, 1 h/day, 5 days/week. The T-N+ and T+N+ groups received nandolone decanoate (20 mg/kg b.w.) once per week, subcutaneously. Subsequently, the rats were sacrificed and muscle specimens were prepared for the processing. Tissue sections were histochemically and immunohistochemically stained, while the image analysis was used for quantification. Longitudinal diameter of quadriceps muscle cells was increased for 21% in T-N+, for 57% in T+N- and for 64% in T+N+ group while cross section muscle cell area was increased in T-N+ for 19%, in T+N- for 47% and in T+N+ group for 59%, compared to the control. Collagen fibers covered area was increased in T-N+ group for 36%, in T+N- for 109% and in T+N+ group for 159%, compared to the control. Erythrocyte depots were decreased in T-N+ group and increased in T+N- and T+N+ group, in comparison with T-N-. VEGF depots were increased in all treated groups. Chronic administration of supraphysiological doses of AASs alone or in combination with physical activity induces hypertrophy and significant changes in the quadriceps muscle tissue structure.