ABSTRACT
AIM:To investigate the role of nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in erectile dysfunction of diabetic rats.METHODS:Type 2 diabetic rat model was established by 4 weeks of high-fat diet plus a single intraperitoneal injection of streptozotocin and continued high-fat diet feeding for 8 weeks.Corpus cavernosum was isolated from the rats under anesthetization,and the endothelium-dependent relaxation response to acetylcholine (ACh) was tested in an organ chamber to reflect erectile function.The level of ADMA in serum was detected.The NOS activity,nitric oxide (NO) content and cyclic guanosine monophosphate (cGMP) content in corpus cavernosum were measured.The protein expression of ADMA-NOS-NO pathway-related molecules and phosphodiesteras 5 (PDES) in the corpus cavernosum was detected by Western blot.Superoxide dismutase activity and malondialdehyde content were analyzed to evaluate oxidative stress.RESULTS:Elevated blood glucose and lowered insulin sensitivity were observed in the diabetic rats,indicating that type 2 diabetic rat model was successfully established.Compared with control group,the relaxation response to ACh of corpus cavernosum from diabetic rats was significantly decreased,which was accompanied with the elevation of serum ADMA level and reduction of NOS activity,NO content and cGMP content in the corpus cavernosum.The protein expression of ADMA-generating enzyme protein arginine methyltransferase 1 was up-regulated,while ADMA-metabolic enzymes dimethylarginine dimethylaminohydrolases 1 and 2,and ADMA-targeting enzymes endothelial NOS and neuronal NOS were down-regulated.The protein expression of PDE5 was up-regulated,accompanied with an increase in oxidative stress in the corpus cavemosum of diabetic rats.Incubation of isolated corpus cavernosum from normal rats with NOS inhibitor ADMA induced the similar relaxation dysfunction of corpus cavemosum response to ACh and decreased NO and cGMP contents in diabetic rats.CONCLUSION:Elevated endogenous NOS inhibitor ADMA plays an important role in erectile dysfunction of diabetic rats.The underlying mechanism may be related to the reduction of NO production and the increase in oxidative stress.
ABSTRACT
AIM:To investigate the role of nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in erectile dysfunction of diabetic rats.METHODS:Type 2 diabetic rat model was established by 4 weeks of high-fat diet plus a single intraperitoneal injection of streptozotocin and continued high-fat diet feeding for 8 weeks.Corpus cavernosum was isolated from the rats under anesthetization,and the endothelium-dependent relaxation response to acetylcholine (ACh) was tested in an organ chamber to reflect erectile function.The level of ADMA in serum was detected.The NOS activity,nitric oxide (NO) content and cyclic guanosine monophosphate (cGMP) content in corpus cavernosum were measured.The protein expression of ADMA-NOS-NO pathway-related molecules and phosphodiesteras 5 (PDES) in the corpus cavernosum was detected by Western blot.Superoxide dismutase activity and malondialdehyde content were analyzed to evaluate oxidative stress.RESULTS:Elevated blood glucose and lowered insulin sensitivity were observed in the diabetic rats,indicating that type 2 diabetic rat model was successfully established.Compared with control group,the relaxation response to ACh of corpus cavernosum from diabetic rats was significantly decreased,which was accompanied with the elevation of serum ADMA level and reduction of NOS activity,NO content and cGMP content in the corpus cavernosum.The protein expression of ADMA-generating enzyme protein arginine methyltransferase 1 was up-regulated,while ADMA-metabolic enzymes dimethylarginine dimethylaminohydrolases 1 and 2,and ADMA-targeting enzymes endothelial NOS and neuronal NOS were down-regulated.The protein expression of PDE5 was up-regulated,accompanied with an increase in oxidative stress in the corpus cavemosum of diabetic rats.Incubation of isolated corpus cavernosum from normal rats with NOS inhibitor ADMA induced the similar relaxation dysfunction of corpus cavemosum response to ACh and decreased NO and cGMP contents in diabetic rats.CONCLUSION:Elevated endogenous NOS inhibitor ADMA plays an important role in erectile dysfunction of diabetic rats.The underlying mechanism may be related to the reduction of NO production and the increase in oxidative stress.
ABSTRACT
This study was aimed to explore the correlation of mean platelet volume (MPV), fibrinogen (FIB) and blood rheology with the youth patients with cerebral infarction, so as to provide the basis for the clinical early diagnosis and treatment. The 109 patients with cerebral infarction aged between 18 - 45 were divided into three group: the large (> 10 cm(3)), middle (4 - 10 cm(3)) and small (< 4 cm(3)) area infarction; 30 healthy persons were served as control group. All the four groups were subjected to 16 examinations, such as MPV, FIB, and rheology (Lηb, Mηb, Hηb, ηp, Lηr, Mηr, Hηr, KVE, EAI, ERI, EDI, EEI, HCT, ESR). The results showed that all the MPV, FIB and rheology indexes of the different infarction groups were higher than those of healthy control group (P < 0.05). The MPV, FIB and rheology indexes in the large area infarction group were all higher than those in the small area infarction group (P < 0.05). The indexes of MPV, FIB and rheology in the various cerebral infarction area groups obviously decreased, but those did not reach to the level in the healthy control group (P < 0.05). The MPV, FIB content and rheology level correlated with infarction areas (r = 0.36, 0.29 and 0.48, respectively). It is concluded that the serious intensity of youth patients with cerebral infarction positively correlated with the levels of MPV, FIB and rheology indexes. Regular examination of above mentioned index may be useful to prevent youth patients from cerebral infraction.