sildenafil-citrate and Hyperglycemia

Type 2 diabetes (T2D) is one of the major risk factors for developing cardiovascular disease and the resultant devastating morbidity and mortality. The key features of T2D are hyperglycemia, hyperlipidemia, insulin resistance, and impaired insulin secretion. Patients with diabetes and myocardial infarction have worse prognosis than those without T2D. Moreover, obesity and T2D are recognized risk factors in developing severe form of COVID-19 with higher mortality rate. The current lines of drug therapy are insufficient to control T2D and its serious cardiovascular complications. Phosphodiesterase 5 (PDE5) is a cGMP specific enzyme, which is the target of erectile dysfunction drugs including sildenafil, vardenafil, and tadalafil. Cardioprotective effects of PDE5 inhibitors against ischemia/reperfusion (I/R) injury were reported in normal and diabetic animals. Hydroxychloroquine (HCQ) is a widely used antimalarial and anti-inflammatory drug and its hyperglycemia-controlling effect in diabetic patients is also under investigation. This review provides our perspective of a potential use of combination therapy of PDE5 inhibitor with HCQ to reduce cardiovascular risk factors and myocardial I/R injury in T2D. We previously observed that diabetic mice treated with tadalafil and HCQ had significantly reduced fasting blood glucose and lipid levels, increased plasma insulin and insulin-like growth factor-1 levels, and improved insulin sensitivity, along with smaller myocardial infarct size following I/R. The combination treatment activated Akt/mTOR cellular survival pathway, which was likely responsible for the salutary effects. Therefore, pretreatment with PDE5 inhibitor and HCQ may be a potentially useful therapy not only for controlling T2D but also reducing the rate and severity of COVID-19 infection in the vulnerable population of diabetics.

Topics: Animals; COVID-19; COVID-19 Drug Treatment; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Hydroxychloroquine; Hyperglycemia; Insulin Resistance; Male; Mice; Myocardial Infarction; Phosphodiesterase 5 Inhibitors; Sildenafil Citrate; Tadalafil; Vardenafil Dihydrochloride

Endothelial dysfunction (ED) plays a role in diabetic cardiovascular complications. Hyperglycemia increases cytockines involved in vascular inflammation. Inhibition of phosphodiesterase type 5 (PDE5) exerts a relaxation on corpora cavernosa and has cardioprotective properties. The effect of chronic sildenafil treatment, on ED markers and metabolic parameters in a non-randomized study on men with type 2 diabetes (T2DM), was investigated.. Twenty-eight T2DM patients (61.2 ± 7.8 years, hemoglobin A1c (HbA1c) 7.9 ± 1.3%, duration of diabetes 11.5 ± 7.8 years) were treated with sildenafil 100 mg/d for 3 months. Baseline and postprandial glycemia, insulin, HbA1c, HOMA index, lipids, glomerular filtration rate, homocysteine were assessed at each visit. P-selectin (CD62P), CD14/42b, CD14/41, ICAM (CD54), PECAM (CD31) and CD11b/CD18, were evaluated, after monocyte isolation with flow-cytometry, before and after treatment.. After 3 months, sildenafil decreased P-selectin (p < 0.05), post-prandial glycemia (p < 0.01), HbA1c (p < 0.01), low-density lipoprotein cholesterol (p < 0.01) and increased high-density lipoprotein (p < 0.05).. PDE5 inhibition, in T2DM patients, reduces the endothelial function marker P-selectin and exerts a beneficial effect on glycometabolic control.

Topics: Aged; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Endothelium, Vascular; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Lipids; Male; Middle Aged; P-Selectin; Phosphodiesterase 5 Inhibitors; Sildenafil Citrate; Vasodilator Agents

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease (ESRD). Hypertension increases kidney stress, which deteriorates function, and leads to peripheral renal vascular resistance. Long-term hypoperfusion promotes interstitial fibrosis and glomerular sclerosis, resulting in nephrosclerosis. Although hypertension and DN are frequent ESRD complications, relevant animal models remain unavailable. We generated a deoxycorticosterone acetate (DOCA)-salt hypertensive uni-nephrectomized (UNx) KKA

Topics: Acetates; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cardiomegaly; Cyclic Nucleotide Phosphodiesterases, Type 4; Cyclic Nucleotide Phosphodiesterases, Type 5; Desoxycorticosterone; Female; Hyperglycemia; Hypertension; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mineralocorticoids; Phosphodiesterase 5 Inhibitors; Renal Insufficiency; Sildenafil Citrate; Sodium Chloride; Tyramine

The goal of this study was to investigate the effect of different phosphodiesterase inhibitors (PDEIs), on renal oxidant/antioxidant balance in diabetic rats. Our study was conducted on 125 rats, diabetes was induced in 100 rats by a single administration of streptozocin (STZ). Diabetic rats were divided into four equal groups. The first group was assigned as diabetic control, the remaining three groups were treated with pentoxifylline, sildenafil and milrinone via drinking water for 15 successive days, another group of 25 normal rats was assigned as non-diabetic control. Significant increase in plasma levels of glucose, urea, creatinine, malondialdehyde (MDA), and nitric oxide (NO) with a concomitant decrease in the levels of insulin, reduced glutathione (GSH), glutathione peroxidase (Gpx), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (TAC) were observed in diabetic rats. These alterations were reverted back to near normal level after treatment with PDEIs. Our data seem to suggest a potential role of PDEIs in maintaining health in diabetes by reducing the progression of diabetic nephropathy.

Topics: Animals; Antioxidants; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Kidney; Lipid Peroxidation; Male; Milrinone; Oxidative Stress; Oxidoreductases; Pentoxifylline; Phosphodiesterase 3 Inhibitors; Phosphodiesterase 5 Inhibitors; Phosphodiesterase Inhibitors; Random Allocation; Rats, Sprague-Dawley; Renal Insufficiency; Sildenafil Citrate

Male infertility prevalence is higher in diabetic patients. Those patients exhibit testicular oxidative damage due to sustained hyperglycemia and inflammation. The study has investigated the efficacy of cilostazol, a phosphodiesterase 3 inhibitor, on testicular damage of diabetic rats.. Streptozotocin-induced diabetes in rats was used as a model. Six control male rats and 24 diabetic male rats were divided into the following: diabetic, cilostazol at low dose, cilostazol at high dose, and sildenafil treated rat groups. Treatment period was 4 weeks. Then, serum testosterone, testicular oxidative parameters, and testicular oxidant defenses were assayed. Real time PCR was done for quantification of Phosphoinositide 3-kinase (PI3K), Akt, and nuclear factor (NF)-κB mRNA. Expression of testicular inducible nitric oxide synthase (iNOS) was assessed.. Diabetes negatively affected the testicular tissue as evident by biochemical analysis and histopathology. Four weeks of cilostazol or sildenafil treatment improved anti-oxidative capacity, ameliorated lipid peroxidation and the pro-inflammatory iNOS expression in testicular tissue. Testosterone level and the spermatogenesis showed marked improvement. Quantitative mRNA expression showed an elevation in PI3K and Akt by cilostazol with decreasing in NF-κB level by both drugs.. Our findings suggest the beneficial role of cilostazol and sildenafil in diabetic testicular damage dependent on anti-inflammatory and anti-oxidant effects.

Topics: Animals; Cilostazol; Diabetes Complications; Diabetes Mellitus, Experimental; Glutathione; Heme Oxygenase (Decyclizing); Hyperglycemia; Infertility, Male; Inflammation; Male; Malondialdehyde; Oxygen; Phosphatidylinositol 3-Kinases; Phosphodiesterase 3 Inhibitors; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Sildenafil Citrate; Streptozocin; Superoxide Dismutase; Testis; Tetrazoles

Diabetes mellitus is characterized by changes in endothelial cells that alter monocyte recruitment, increase classic (M1-type) tissue macrophage infiltration and lead to self-sustained inflammation. Our and other groups recently showed that chronic inhibition of phosphodiesterase-5 (PDE5i) affects circulating cytokine levels in patients with diabetes; whether PDE5i also affects circulating monocytes and tissue inflammatory cell infiltration remains to be established. Using murine streptozotocin (STZ)-induced diabetes and in human vitro cell-cell adhesion models we show that chronic hyperglycemia induces changes in myeloid and endothelial cells that alter monocyte recruitment and lead to self-sustained inflammation. Continuous PDE5i with sildenafil (SILD) expanded tissue anti-inflammatory TIE2-expressing monocytes (TEMs), which are known to limit inflammation and promote tissue repair. Specifically, SILD: 1) normalizes the frequency of circulating pro-inflammatory monocytes triggered by hyperglycemia (53.7 ± 7.9% of CD11b+Gr-1+ cells in STZ vs. 30.4 ± 8.3% in STZ+SILD and 27.1 ± 1.6% in CTRL, P<0.01); 2) prevents STZ-induced tissue inflammatory infiltration (4-fold increase in F4/80+ macrophages in diabetic vs. control mice) by increasing renal and heart anti-inflammatory TEMs (30.9 ± 3.6% in STZ+SILD vs. 6.9 ± 2.7% in STZ, P <0.01, and 11.6 ± 2.9% in CTRL mice); 3) reduces vascular inflammatory proteins (iNOS, COX2, VCAM-1) promoting tissue protection; 4) lowers monocyte adhesion to human endothelial cells in vitro through the TIE2 receptor. All these changes occurred independently from changes of glycemic status. In summary, we demonstrate that circulating renal and cardiac TEMs are defective in chronic hyperglycemia and that SILD normalizes their levels by facilitating the shift from classic (M1-like) to alternative (M2-like)/TEM macrophage polarization. Restoration of tissue TEMs with PDE5i could represent an additional pharmacological tool to prevent end-organ diabetic complications.

Topics: Animals; Cell Adhesion; Cell Communication; Cell Count; Coculture Techniques; Cyclic Nucleotide Phosphodiesterases, Type 5; Cyclooxygenase 2; Diabetes Mellitus, Experimental; Endothelial Cells; Gene Expression Regulation; Hyperglycemia; Macrophages; Male; Mice; Monocytes; Nitric Oxide Synthase Type II; Phosphodiesterase 5 Inhibitors; Protective Agents; Receptor, TIE-2; Signal Transduction; Sildenafil Citrate; Streptozocin; Vascular Cell Adhesion Molecule-1

Acute hyperglycemia disrupts gastric myoelectric rhythm in healthy humans. Defective nitrergic function is a factor in animal models of diabetic gastropathy. We tested participation of nitrergic pathways in hyperglycemia-evoked myoelectric dysrhythmias and compared their role in preventing dysrhythmic actions of experimental motion sickness. Twelve healthy volunteers underwent electrogastrography (EGG) with and without intravenous 20% dextrose to produce plasma glucoses of 250 mg/dl. EGG continued for 2 h after oral nitroglycerin (9 mg) or the cyclic GMP-specific phosphodiesterase inhibitor sildenafil (100 mg). In separate studies, 12 volunteers underwent circular vection (60 degrees /s) without and 90 min after nitroglycerin (9 mg) or sildenafil (100 mg) with concurrent EGG. Hyperglycemia decreased recording time in normal rhythm, increased tachygastria more than 3-fold, and decreased power of the dominant frequency (P < 0.05). Nitroglycerin and sildenafil reversed effects of hyperglycemia, improving normal rhythm, decreasing tachygastria (both P < 0.05), and blunting power decreases. Neither agent affected EGG rhythm during euglycemia. Vection decreased time in normal rhythm and increased tachygastria (P < 0.05). However, nitroglycerin and sildenafil did not reverse dysrhythmic effects of vection (P = N.S.). In conclusion, administration of a nitric oxide (NO) donor or an inhibitor of cyclic GMP-selective phosphodiesterase reverses the dysrhythmic effects of hyperglycemia on gastric myoelectric activity in healthy humans. These agents have no effect on dysrhythmias during motion sickness. These findings are consistent with selective impairment of nitrergic function in this model of diabetic gastropathy and suggest that NO donors and other agents that increase NO activity may be useful for treating diabetic dysrhythmias.

Topics: Adult; Blood Glucose; Constriction; Female; Gastrointestinal Motility; Humans; Hyperglycemia; Male; Middle Aged; Nitroglycerin; Ovum; Piperazines; Purines; Sildenafil Citrate; Sulfones