AGE-breaker ALT-711 plus insulin could restore erectile function in streptozocin-induced type 1 diabetic rats.

The interaction between advanced glycation end-products (AGEs) and its receptors for AGEs (RAGEs) elicits oxidative stress and mediates the development of erectile dysfunction (ED). ALT-711, an AGE cross-link breaker, has the therapeutic potential for ED but has been less intensively investigated. The aim of this study was to investigate the effects of an AGEs breaker 3-phenacyl-4,5-dimethylthiazolium chloride (ALT-711) plus insulin on erectile function in streptozocin (STZ)-induced type 1 diabetic rats. Fifty 8-week-old Sprague-Dawley rats were randomly distributed into five groups: normal control (C), diabetic (D), insulin-treated diabetic (D + I), ALT-711-treated diabetic (D + ALT-711) and insulin plus ALT-711-treated diabetic (D + I + ALT-711) rats. Diabetes was induced by a single intraperitoneal injection of STZ. Eight weeks after induction of diabetes, ALT-711 was administered by intraperitoneal injection. Two to six units of intermediate-acting insulin were utilized to achieve normal levels of glycemic control. After treatment for 6 weeks, erectile function was determined via measurement of intracavernous pressures (ICPs) following electrostimulation of the cavernous nerve. The deposition of AGEs, expression of RAGEs, superoxide dismutase activity, and lipid peroxidation were measured. We also evaluated penile histological changes such as smooth muscle contents, endothelial cells contents, and apoptotic activity. The main outcome measures were the ratio of ICP/mean arterial pressure (MAP), penile endothelial cells, smooth muscle cells, neuronal nitric oxide synthase, AGE and RAGE expression, malondialdehyde concentration, SOD activity, and apoptosis index. Diabetic rats demonstrated significantly reduced ICP/MAP ratio, penile endothelial cells, smooth muscles cells, increased AGEs and RAGE expression, and increased apoptosis. Insulin and ALT-711 monotherapy partially restored erectile function and histological changes. However, the combination therapy group showed erectile parameters and components similar to those in C. ALT-711-treated group demonstrated less deposition of AGEs and lower expression of RAGE than those in insulin-treated group. These results suggest that although insulin can effectively control glycemic levels, it does not completely alter the pathological changes in erectile tissues. Better efficacy could be expected with tight glycemic control plus ALT-711, an AGEs cross-link breaker. The combination therapy might have the potential to eliminate metabolic memory by down-regulating the AGEs-RAGE oxidative stress axis.

Wang L ，Tian W ，Uwais Z ，Li G ，Li H ，Guan R ，Gao Z ，Xin Z ... -  《-》

Antioxidant icariside II combined with insulin restores erectile function in streptozotocin-induced type 1 diabetic rats.

Erectile dysfunction (ED) worsens in patients with diabetes mellitus (DM) despite good control of blood glucose level with insulin. Recent studies imply that diabetic vascular stresses (e.g. oxidative stress) persist in spite of glucose normalization, which is defined as metabolic memory. Studies suggest that the interaction between advanced glycation end products (AGEs) and their receptor (RAGE) mediates the development of metabolic memory. To investigate the effects of the antioxidant icariside II plus insulin on erectile function in streptozotocin (STZ)- induced type 1 diabetic rats. Fifty 8-week-old Sprague-Dawley rats were randomly distributed into five groups: normal control, diabetic, insulin-treated diabetic, icariside II-treated diabetic, and insulin plus icariside II-treated diabetic. Diabetes was induced by a single intraperitoneal injection of STZ. Eight weeks after induction of diabetes, icariside II was administered by gastric lavage once a day (5 mg/kg) for 6 weeks; and 2-6 units of intermediate-acting insulin were given to maintain normal glycemia for 6 weeks. The main outcome measures were the ratio of intracavernous pressure (ICP) to mean arterial pressure (MAP); histology of penile endothelial cells and smooth muscle cells; neural nitric oxide synthase, AGEs and RAGE expression; malondialdehyde concentration; superoxide dismutase activity; and apoptosis index. Diabetic rats demonstrated a significantly lower ICP/MAP ratio, reduced penile endothelial cells, reduced smooth muscle cells, increased AGEs and RAGE, and increased apoptosis. Insulin and icariside II monotherapy partially restored erectile function and histological changes. However, the combination therapy group showed significantly better erectile parameters, cytological components and biochemistry, similar to those in the normal control group. These results suggest that, although insulin can effectively control glycemic levels, it does not completely alter the pathological changes in erectile tissues. Better efficacy could be expected with tight glycemic control plus the antioxidant icariside II. The proposed combination therapy might have the potential to eliminate metabolic memory by down-regulating the AGEs-RAGE-oxidative stress axis.

Wang L ，Xu Y ，Li H ，Lei H ，Guan R ，Gao Z ，Xin Z ... -  《-》

Therapeutic effect of combination of alagebrium (ALT-711) and sildenafil on erectile function in diabetic rats.

Gurbuz N ，Sagdic G ，Sanli A ，Ciftcioglu A ，Bassorgun I ，Baykal A ，Usta MF ... -  《-》

Effects of icariside II on improving erectile function in rats with streptozotocin-induced diabetes.

Zhou F ，Xin H ，Liu T ，Li GY ，Gao ZZ ，Liu J ，Li WR ，Cui WS ，Bai GY ，Park NC ，Xin ZC ... -  《-》

Effects of adipose-derived stem cells plus insulin on erectile function in streptozotocin-induced diabetic rats.

Zhou F ，Hui Y ，Xu Y ，Lei H ，Yang B ，Guan R ，Gao Z ，Xin Z ，Hou J ... -  《-》