Inosine Protects Bladder Structure And Function In Rats With Diabetic Cystopathy

Diabetic cystopathy(DCP),also known as diabetic neurogenic bladder disease(DNB),is a common chronic complications of diabetes.In 2004,Lee et al used statistic mothod and found that the prevalenc of diabetic patients with bladder disease was 25% ~ 90%.In 2011,22.5% of diabetic patients had overactive bladder,of which 48.0% were urinary incontinence.The pathogenesis of DCP mainly includes neuropathy,detrusor myogenic lesions and oxidative stress injury.And oxidative stress injury is an important factor in the damage of bladder function in diabetic patients.Increasing the clearance rate of oxygen free radicals may help to improve the diabetic animal's Neurovascular damage,the treatment of DCP is still a lack of effective means to find natural antioxidants has become a hot research.Inosine is widely used for many years in clinical practice without obvious adverse drug reactions.A large number of studies have shown that inosine can effectively counteract the oxidative stress and damage to the body and increase the tolerance of cells to hypoxia and ischemia.Mechanotransduction,the conversion of mechanical forces into biological signals,plays critical roles in various physiological and pathophysiological processes in mammals,such as conscious sensing of touch,pain,and sound,as well as unconscious sensing of urine flow,and bladder distention.Mechanosensitive(MS)channels represent a class of ion channels that gate upon mechanical force stimulation.Piezo is a new type of mechanosensitive channel discovered recently,and it is involved in transferring mechanical signals on the membrane into electrical signals or chemical signals.In the mammals,the channels family contained the Piezo1 and Piezo2 proteins,encoded by the FAM38 A and FAM38 B genes,respectively.The two mammalian isoforms are abundantly expressed in a wide range of mechanically sensitive tissue and cells,including bladder,kidneys,red blood cells,dorsal root ganglia(DRG)sensory neurons and Merkel cells.Piezo2 are found in the dorsal root ganglia,which play essential roles in bladder sensation.Diabetic cystopathy(DCP)is one of the common complications of diabetic urinary system,characterized by voiding dysfunction,increased capacity,reduced detrusor contraction and increased residual urine.Currently,there are few reports regarding Piezo channels and DCP.In this study,diabetic rat models are induced by streptozotocin(STZ).The changes of Piezo channels gene expressions and protein levels in diabetic rats bladder tissue are examined,in order to explore the pathophysiological mechanism of the changes of sensory signaling the DCP,and provide a theoretical basis for clinical treatment.PART ?: Morphological Analysis of Inosine in Treatment of Diabetic cystopathy and Measurement of Related Oxidative IndexesObjective: At present,the treatment of diabetic cystopathy(DCP)is still lack of effective means,and finding natural antioxidants has become a hot research.This research is aim to discuss the positive efficacy of inosine on a diabetic rat bladder and explore antioxidant stress mechanism.Investigate whether inosine is able to reverse the oxidative damage and protect bladder function in diabetic rats.Methods: A total of 60 SD rats were randomly divided into 3 groups: Normal controls group(NC),Diabetic rats group(DM)and inosine treatment group(INOSINE).The last two groups were both by injected of STZ,60mg/kg,by a single intraperitoneal,NC group injected by a considerable volume of citric acid buffer correspondingly.one week after the injection,the Inosine group accepted 4 and 8weeks of treatment with inosine(75mg/kg,ip,bid),and DM Group with saline.measured the weight and blood glucose of the rats in three groups once a week.The tissues of the rats bladders were examined for structural changes using HE staining,Electron microscopy and TUNEL.The expressions of nerve growth factor and c-kit was investigated by immunofluorescence method.Then oxidative stress indicators detected by the kits.Result: The bladder detrustor were significantly improved by inosine,and inosine significantly constrained the increased of MDA but increased the activities of SOD and GSH.Conclusion: Inosine has a beneficial effect on DCP by ameliorating oxidative stress in the diabetic rats bladders.PART ?: Effect of inosine on the piezo ion channels in the bladder tissue of diabetic ratsObjective: To investigate the time-dependent expression and distribution of Piezo ion channels and the effect of inosine on the piezo ion channels in the bladder tissue of diabetic rats.Methods: a total of 54 Eight-week-old male SD rats were allocated into 3 groups randomly: normal controls group(NC),diabetes mellitus group(DM)and diabetes mellitus with inosine treatment group(INOSINE).DM and INOSINE groups were injected STZ,60 mg/kg,by intraperitoneal,but NC group were injected with an equal volume of vehicle(0.1 M citrate buffer solution)correspondingly.Seven days after the injection of STZ,the blood glucose level was measured.When the blood glucose level was higher than 16.7mmol / L,the rat was considered to be diabetic and was used in the following experiments.The level of blood glucose and body weight were measured once a week.Subsequently,the rats were humanely killed at 1,2 or 8 weekpoints(6 rats each)and the bladders were harvested for measurements.The expressions of Piezo1 and Piezo2 mRNA in the bladder tissue were analyzed by Real-time PCR.The changes of piezo1 and piezo 2 protein levels in the bladder were analyzed by Western Blot assay.And piezo1 and c-kit expressions were observed by immunofluorescence staining.Results: At 1 and 2 weekpoints after diabetes induction,the expressions of the mRNA and protein of Piezo1 and Piezo2 in DM were significantly higher than those in INOSINE and NC(P <0.05),however at 8 weekpoint after diadetes,there is no obviously different change(P> 0.05).Conclusion: The expression levels of Piezo1 and Piezo2 in the rat`s bladder tissue can be significantly increased in the early stage of diabetic cystopathy,and these may be important factors of the lower urinary tract symptoms.Inosine can significantly inhibit Piezo1 and Piezo2 increases to protect bladder function.