Increased phosphodiesterase type 5 levels in a mouse model of type 2 diabetes mellitus

Medicine has always been "Modern" and "Scientific" from ancient times to the present day

Throughout human history, doctors and healers have gathered and refined the knowledge inherited from the previous generations. Different methods of effective therapy have been designed during various historical periods; when each was developed, it was considered "modern scientific medicine" for their time. Mankind has gone through natural and social disasters and survived; hence, history has proved there was no time when medical knowledge was erroneous or ineffective. Classic medicine has grown to be divided into narrow, specialized branches, causing it to lose its holistic approach and general view on health, sickness and therapeutic methods. Many of traditional medicine's effective methods have been forgotten and removed from the mainstream medicine. It would be good for modern medical education to incorporate the general knowledge of historically effective therapeutic modalities and study practical cases. Medical students should be taught how to choose a "good method" or "good medicine" independent of when that method or remedy was discovered. However, he has to keep in mind the primary goal of medicine: "I will use treatment to help the sick according to my ability and judgment…"(from Hippocratic Oath).

Effect of low-energy shockwave therapy on angiogenic factors in the penile tissue of diabetic rats

OBJECTIVE

The aim of this study is to investigate the effect of low-energy shock wave therapy (LESWT) on angiogenesis factors at penile tissue in a diabetic rat model.

MATERIAL AND METHODS

A total of 30 male Sprague-Dawley rats which were allocated into three equal groups were included study. Group 1 (control group) included 10 male rats which did not receive any treatment were randomly chosen to serve as normal control. The remaining rats were injected intraperitoneally with 60 mg/kg of streptozotocin (STZ) to induce diabetes. Diabetic rats were divided into two equal group which constituted diabetic control, and LESWT treatment (DM+LESWT) group. Each rat in the DM+LESWT group received L-ESWT therapy. Endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) mRNA expression levels of penile tissue were evaluated.

RESULTS

Following STZ dosing eNOS level dropped in the diabetic control group relative to the control group. Statistically significant increase in eNOS levels were seen in the LESWT+DM group. Similarly, in the diabetic control group STZ treatment decreased VEGF levels, while in the LESWT+DM group VEGF nearly approached to baseline levels. However variations in VEGF levels were not statistically significant.

CONCLUSION

Mechanism action of ESWT in the penile tissue seems to involve angiogenic factors.

Constitutive NOS uncoupling and NADPH oxidase upregulation in the penis of type 2 diabetic men with erectile dysfunction

Erectile dysfunction (ED) associated with type 2 diabetes mellitus (T2DM) involves dysfunctional nitric oxide (NO) signaling and increased oxidative stress in the penis. However, the mechanisms of endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS) dysregulation, and the sources of oxidative stress, are not well defined, particularly at the human level. The objective of this study was to define whether uncoupled eNOS and nNOS, and NADPH oxidase upregulation, contribute to the pathogenesis of ED in T2DM men. Penile erectile tissue was obtained from 9 T2DM patients with ED who underwent penile prosthesis surgery for ED, and from six control patients without T2DM or ED who underwent penectomy for penile cancer. The dimer-to-monomer protein expression ratio, an indicator of uncoupling for both eNOS and nNOS, total protein expressions of eNOS and nNOS, as well as protein expressions of NADPH oxidase catalytic subunit gp91phox (an enzymatic source of oxidative stress) and 4-hydroxy-2-nonenal [4-HNE] and nitrotyrosine (markers of oxidative stress) were measured by western blot in this tissue. In the erectile tissue of T2DM men, eNOS and nNOS uncoupling and protein expressions of NADPH oxidase subunit gp91phox, 4-HNE- and nitrotyrosine-modified proteins were significantly (p < 0.05) increased compared to control values. Total eNOS and nNOS protein expressions were not significantly different between the groups. In conclusion, mechanisms of T2DM-associated ED in the human penis may involve uncoupled eNOS and nNOS and NADPH oxidase upregulation. Our description of molecular factors contributing to the pathogenesis of T2DM-associated ED at the human level is relevant to advancing clinically therapeutic approaches to restore erectile function in T2DM patients.

Effect of phosphodiesterase-5 inhibitors on glycemic control in person with type 2 diabetes mellitus: A systematic review and meta-analysis

Chronic use of phosphodiesterase-5 inhibitors (PDE-5i) has been shown to improve insulin action on muscle glucose uptake by the prolongation of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP)/protein kinase (PKG) signalling.

Aims

As the effects of PDE-5i on glycemic control in person with type 2 diabetes mellitus (T2DM) have not been systematically explored, we conducted a meta-analysis of available randomized controlled trials (RCTs).

Methods

A literature search was performed through electronic databases including MEDLINE (Pubmed), The Cochrane Library, SCOPUS, Web of Science, CINAHL, www.clinicaltrials.gov and www.clinicaltrialresults.org until April 2016 without language restriction. Studies were included if they met the following criteria: (i) RCTs of the chronic use of PDE-5i compared with placebo or no active treatment in T2DM patients (ii) reporting of HbA1c or glycated haemoglobin or fasting plasma glucose (FPG).

Results

Four studies involving a total of 198 patients fit into the inclusion criteria. All included studies used the same PDE-5i, sildenafil. Reports of HbA1c were analysed as only one study reported FPG. PDE-5i had no beneficial effect on HbA1c with weighted mean difference (WMD) of 0.17% (95% CI, −0.64 to 0.97).

Conclusion

This meta-analysis suggests that large and well-controlled studies are warranted to shed light on the effect of PDE-5i on glycemic control in people with type 2 diabetes mellitus.

Clinical significance and expression of microRNA in diabetic patients with erectile dysfunction

The aim of the present study was to investigate the expression of microRNA (miR)-93, miR-320 and miR-16 and to assess their diagnostic value in diabetic patients with erectile dysfunction (ED). A total of 120 individuals were divided into three groups, which included the diabetics with ED group (ED group), the diabetics without ED group (NED group) and the healthy volunteers group (control group). Each group included 40 individuals. Serum samples were collected and reverse transcription quantitative polymerase chain reaction detection of the three types of miRNA was performed and the sensitivity of ED was analyzed by receiver operating characteristic curves. A negative correlation was identified between the incidence of ED in patients with diabetes and serum total testosterone levels (r=0.302, P<0.05); however, a positive correlation was observed between the incidence of ED in diabetics and the HbA1c level (r=0.231, P<0.05). Additionally, the relative expression levels of the three types of miRNA were higher in the ED group when compared with the NED and control groups (P<0.05). When compared with the control group, the area under the curve (AUC) values for miR-93, miR-320 and miR-16 were 0.793, 0.818 and 0.810, respectively, in the ED group and 0.576, 0.532 and 0.542 in the NED group, respectively. Furthermore, when compared with the NED group, the AUC value for miR-93, miR-320 and miR-16 was 0.707, 0.810 and 0.833, respectively, in the ED group. Therefore, the expression levels of miR-93, miR-320 and miR-16 may be useful for the early diagnosis of ED in patients with diabetes.