Diabetic nephropathy is a microvascular complication of diabetes. Its etiology involves metabolic disorder-induced endothelial dysfunction. Endothelium-derived nitric oxide (NO) plays an important role in a number of physiological processes, including glomerular filtration and endothelial protection. NO dysregulation is an important pathogenic basis of diabetic nephropathy. Hyperglycemia and dyslipidemia can lead to oxidative stress, chronic inflammation and insulin resistance, thus affecting NO homeostasis regulated by endothelial nitric oxide synthase (eNOS) and a conglomerate of related proteins and factors. The reaction of NO and superoxide (O₂^.-) to form peroxynitrite (ONOO^-) is the most important pathological NO pathway in diabetic nephropathy. ONOO^- is a hyper-reactive oxidant and nitrating agent in vivo which can cause the uncoupling of eNOS. The uncoupled eNOS does not produce NO but produces superoxide. Thus, eNOS uncoupling is a critical contributor of NO dysregulation. Understanding the regulatory mechanism of NO and the effects of various pathological conditions on it could reveal the pathophysiology of diabetic nephropathy, potential drug targets and mechanisms of action. We believe that increasing the stability and activity of eNOS dimers, promoting NO synthesis and increasing NO/ONOO^- ratio could guide the development of drugs to treat diabetic nephropathy. We will illustrate these actions with some clinically used drugs as examples in the present review.
Diabetes Mellitus ; Diabetic Nephropathies/drug therapy* ; Endothelium, Vascular ; Humans ; Nitric Oxide/metabolism* ; Nitric Oxide Synthase Type III/therapeutic use* ; Oxidative Stress ; Peroxynitrous Acid/therapeutic use*

Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Animals ; Benzimidazoles ; therapeutic use ; Hypertension ; blood ; drug therapy ; Male ; Nitric Oxide ; blood ; Nitric Oxide Synthase Type III ; blood ; Random Allocation ; Rats ; Rats, Inbred SHR ; Tetrazoles ; therapeutic use ; Urotensins ; blood

AIMTo investigate the effect of Safflor yellow on the gene expression of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in neonatal asphyxia.

METHODS30 minutes after SY 7 g/kg weight intraperitoneally was administered on the neonatal rats. After asphyxia for 40 minutes,the neonatal rats were reoxygenated for 48 h, and the nitric oxide synthases (NOSs) mRNA expression was assessed by semi-quantitative reverse transcription-polymerase chain reaction.

RESULTSNeuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) were up in hypoxia/reoxygenation (H/R) 48 h group, while both of them were down significantly in SY group, but no change was observed on endothelial nitric oxide synthase (eNOS).

CONCLUSIONThe protective of SY from brain damage induced by neonatal asphyxia might be associated with expression of NOSs mRNA.

Animals ; Brain ; metabolism ; Chalcone ; analogs & derivatives ; pharmacology ; therapeutic use ; Gene Expression ; Hypoxia ; metabolism ; prevention & control ; Nitric Oxide Synthase Type I ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Quinones ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of TSG on the content of nitric oxide synthase and the expression of endothelium nitric oxide synthase in artery vessels of experimental atherosclerotic rats.

METHODThe atherosclerosis model of rat was made by feeding high grease food and injecting Vit D3. Sixty male rats were randomly divided into six groups: normal control; model control; TSG high dose; TSG middle dose; TSG low dose; Simvastatin. After 12 weeks, several aorta were randomly tested, and the model made was successful when we found plaque. And after six weeks of treatment, the levels of NOS in serum were measured with a biochemical method. The biochemical method was adopted to detect the content of nitric oxide synthase and half-quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect eNOS and iNOS gene expression in artery vessels.

RESULTData of the study demonstrated that compared with model group, the activity of NOS and the gene expression of eNOS were increased remarkably, and however the gene expression of iNOS was reduced markedly in simvastatin group and TSG 60, 120 mg x kg(-1) x d(-1) group.

CONCLUSIONTSG can enhance the expression of eNOS gene and reduce the expression of iNOS gene in aorta vessels of experimental atherosclerotic rats, which may be one of the anti-atherosclerosis mechanisms of TSG.

Animals ; Arteries ; drug effects ; metabolism ; pathology ; Atherosclerosis ; drug therapy ; enzymology ; pathology ; Gene Expression Regulation, Enzymologic ; drug effects ; Glucosides ; pharmacology ; therapeutic use ; Male ; Nitric Oxide Synthase ; genetics ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Stilbenes ; pharmacology ; therapeutic use

Erectile dysfunction (ED) associated with type 2 diabetes is a severe problem that requires effective treatment. Pancreatic kininogenase (PK) has the potential to improve the erectile function of ED patients. This study aims to investigate the effect of PK on erectile function in streptozotocin-induced type 2 diabetic ED rats. To achieve this goal, we divided male Sprague-Dawley rats into five groups. One group was not treated, and the other four groups were treated with saline, sildenafil, PK or sildenafil, and PK, respectively, for 4 weeks after the induction of type 2 diabetic ED. Then, intracavernous pressure under cavernous nerve stimulation was measured, and penile tissue was collected for further study. Endothelial nitric oxide synthase levels, smooth muscle content, endothelium content, cyclic guanosine monophosphate (cGMP) levels in the corpus cavernosum, and neuronal nitric oxide synthase levels in the dorsal penile nerve were measured. Improved erectile function and endothelium and smooth muscle content in the corpus cavernosum were observed in diabetic ED rats. When treating diabetic ED rats with PK and sildenafil at the same time, a better therapeutic effect was achieved. These data demonstrate that intraperitoneal injection of PK can improve erectile function in a rat model of type 2 diabetic ED. With further research on specific mechanisms of erectile function improvement, PK may become a novel treatment for diabetic ED.
Animals ; Cyclic GMP/metabolism* ; Diabetes Mellitus, Experimental/physiopathology* ; Erectile Dysfunction/physiopathology* ; Kallikreins/therapeutic use* ; Male ; Muscle, Smooth, Vascular/physiopathology* ; Nitric Oxide Synthase Type I/metabolism* ; Nitric Oxide Synthase Type III/metabolism* ; Penile Erection/physiology* ; Penis/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sildenafil Citrate/therapeutic use* ; Treatment Outcome ; Urological Agents/therapeutic use*

OBJECTIVETo study the protective mechanism of Huoxue Anxin Recipe (HAR) on peroxidation damage of acute myocardial infarction (AMI) rats.

METHODSThe AMI rat model was established by occluding the left anterior descending coronary artery. Compound Danshen Dripping Pill (CDDP) was used as the positive control. CDDP and HAR were administered to rats for 7 successive days since modeling. The heart function was detected using color Doppler echocardiography. Activities of induced nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), total superoxide dismutase (tSOD) activity, and contents of malondialdehyde (MDA) were detected by ultraviolet spectrophotometer method.

RESULTSCompared with the sham-operation group, ejection fraction (EF) and fraction shortening (FS) rate significantly decreased in the model group (P < 0.01). Compared with the model group, EF and FS rate significantly increased in the HAR group, showing statistical difference (P < 0.05). There was no statistical difference in activities of serum iNOS, eNOS, or tSOD among all groups (P > 0.05). Compared with the sham-operation group, iNOS activities and MDA contents significantly increased in the myocardial tissue of the model group (P < 0.01), activities of eNOS and tSOD significant decreased (P < 0.01). Compared with the model group, iNOS activities in the myocardial tissue, MDA contents both in serum and the myocardial tissue significantly decreased (P < 0.05), activities of eNOS and tSOD significantly increased in the HAR group (P < 0.05). There was no statistical difference in each index between the CDDP group and the HAR group (P > 0.05).

CONCLUSIONSHAR could significantly improve cardiac functions of AMI rats. Its roles might be associated with regulating imbalanced iNOS/eNOS expressions and alleviating peroxidation damage of the myocardial tissue.

Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Male ; Malondialdehyde ; metabolism ; Myocardial Infarction ; drug therapy ; metabolism ; Myocardium ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Oxidative Stress ; Phytotherapy ; Rats ; Rats, Wistar ; Superoxide Dismutase ; metabolism

This study investigated the role of angiotensin II receptor blocker in atrial remodeling in rats with atrial fibrillation (AF) induced by a myocardial infarction (MI). MIs were induced by a ligation of the left anterior descending coronary artery. Two days after, the rats in the losartan group were given losartan (10 mg/kg/day for 10 weeks). Ten weeks later, echocardiography and AF induction studies were conducted. Ejection fraction was significantly lower in the MI rats. Fibrosis analysis revealed much increased left atrial fibrosis in the MI group than sham (2.22 +/- 0.66% vs 0.25 +/- 0.08%, P = 0.001) and suppression in the losartan group (0.90 +/- 0.27%, P 0.001) compared with the MI group. AF inducibility was higher in the MI group than sham (39.4 +/- 43.0% vs 2.0 +/- 6.3%, P = 0.005) and significantly lower in losartan group (12.0 +/- 31.6%, P = 0.029) compared with the MI. The left atrial endothelial nitric oxide synthase (NOS) and sarco/endoplasmic reticulum Ca(2+)-ATPase levels were lower in the MI group and higher in the losartan group significantly. The atrial inducible NOS and sodium-calcium exchanger levels were higher in the MI and lower in the losartan group significantly. Losartan disrupts collagen fiber formation and prevents the alteration of the tissue eNOS and iNOS levels, which prevent subsequent AF induction.
Angiotensin Receptor Antagonists/*therapeutic use ; Animals ; Atrial Fibrillation/*prevention & control ; Atrial Remodeling ; Disease Models, Animal ; Fibrosis ; Heart Failure/*etiology/ultrasonography ; Immunohistochemistry ; Losartan/*therapeutic use ; Male ; Myocardial Infarction/*complications/ultrasonography ; Nitric Oxide Synthase Type II/metabolism ; Nitric Oxide Synthase Type III/metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Angiotensin/chemistry/metabolism ; Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism ; Sodium-Calcium Exchanger/metabolism

OBJECTIVETo investigate the effect and mechanism of Compound Salvia injection (CSI) on nitrate ester tolerance.

METHODSEighty-four patients with coronary heart disease (CHD) were randomly divided into three groups, Group A treated with isosorbide dinitrate (ISD, 15 mg, 4 times per day) alone, Group B with ISD plus CSI and Group C with ISD plus vitamin C. The therapeutic course for all groups was 10 days. The tolerance to nitrate ester and blood pressure were monitored. Before and after treatment, the color Doppler ultrasonic apparatus was used to detect the baseline value of humeral arterial internal diameters (D0), the humeral arterial dilatory response under compression [D1, that is, the flow-mediated vasodilation (FMD)] and the vasodilatory response after sucking of nitroglycerin (D2). And the blood levels of endothelin-1 (ET-1), endothelial nitric oxide synthase (eNOS) mRNA expression were determined. The endothelial-dependent vasodilation (EDD) was expressed by (D1 - D0)/D0 x 100%, and the endothelial-independent vasodilation (EID) was expressed by (D2 - D0)/D0 x 100%.

RESULTS(1) The occurrence rate of nitrate tolerance in Group B and C (28.57% and 35.7%) was lower than that in Group A (64.29%), but insignificant difference was found between the former two. (2) After treatment, blood pressure increased in Group A to the level of pre-treatment, that in Group C also increased but still lower than that of pre-treatment, while insignificant increase was observed in Group B, comparison between Group B and C showed significant difference (P < 0.05). (3) After treatment, EID lowered in Group A, EDD increased in Group B and C (P < 0.05), EDD and EID in Group B and C were higher than those in Group A (P < 0.05), and EDD was higher in Group B than in Group C (P < 0.05). (4) After treatment, ET-1 mRNA expression lowered in Group B, eNOS mRNA expression increased in Group B and C, with significant difference as compared with those before treatment and those in Group A (P < 0.05), and eNOS mRNA expression in Group C was lower than that in Group B (P < 0.05).

CONCLUSIONCSI could partially prevent the occurrence of tolerance to nitrate ester, with the effect better than vitamin C, the mechanism might be related with its regulation on eNOS, ET-1 mRNA expression and protection on vascular endothelial function.

Adult ; Aged ; Coronary Disease ; drug therapy ; Drug Resistance ; Drugs, Chinese Herbal ; administration & dosage ; Endothelin-1 ; biosynthesis ; genetics ; Female ; Humans ; Injections, Intravenous ; Isosorbide Dinitrate ; therapeutic use ; Male ; Middle Aged ; Nitric Oxide Synthase ; biosynthesis ; genetics ; Nitric Oxide Synthase Type III ; Phytotherapy ; RNA, Messenger ; biosynthesis ; genetics ; Salvia miltiorrhiza ; Vasodilator Agents ; therapeutic use

OBJECTIVENitric oxide (NO) was speculated to play an important role in the pathophysiology of cerebral ischemia. Minocycline, a tetracycline derivative, reduced inflammation and protected against cerebral ischemia. To study the neuroprotection mechanism of minocycline for vascular dementia, the influences of minocycline on expressions of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were observed in the brains of Wistar rats.

METHODSThe vascular dementia rat model was established by permanent bilateral common carotid arteries occlusion (BCCAO). Wistar rats were divideded into 3 groups randomly: sham-operation group (S group), vascular dementia model group (M group), and minocycline treatment group (MT group). The behaviour was tested with Morris water maze and open-field task. Expressions of iNOS and eNOS were measured by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). The optical density value was measured by imaging analysis. Percentage of positive cells with iNOS and eNOS expression was analyzed with optical microscope.

RESULTSMinocycline attenuated cognitive impairment. Inducible NOS was significantly down-regulated in MT group, compared with that in M group (P < 0.01), while eNOS was significantly up-regulated, compared with that in M group (P < 0.01). The expressions of iNOS and eNOS in M and MT groups were higher than those in S group (P < 0.01).

CONCLUSIONMinocycline can down-regulate the expression of iNOS and up-regulate the expression of eNOS in vascular dementia, which restrains apoptosis and oxidative stress to protect neural function.

Animals ; Behavior, Animal ; drug effects ; Carotid Artery Diseases ; complications ; Carotid Artery, Common ; Cognition Disorders ; drug therapy ; etiology ; pathology ; Disease Models, Animal ; Exploratory Behavior ; drug effects ; Female ; Hippocampus ; drug effects ; physiopathology ; Maze Learning ; drug effects ; Minocycline ; therapeutic use ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Oxidative Stress ; drug effects ; Rats ; Rats, Wistar ; Reaction Time ; drug effects ; Time Factors

OBJECTIVE: To explore the therapeutic mechanism of tanshinone IIA in the treatment of pulmonary arterial hypertension (PAH) in rats. METHODS: A total of 100 male SD rats were randomized into 5 groups (n=20), and except for those in the control group with saline injection, all the rats were injected with monocrotaline (MCT) on the back of the neck to establish models of pulmonary hypertension. Two weeks after the injection, the rat models received intraperitoneal injections of tanshinone IIA (10 mg/kg), phosphatidylinositol 3 kinase (PI3K) inhibitor (1 mg/kg), both tanshinone IIA and PI3K inhibitor, or saline (model group) on a daily basis. After 2 weeks of treatment, HE staining and α-SMA immunofluorescence staining were used to evaluate the morphology of the pulmonary vessels of the rats. The phosphorylation levels of PI3K, protein kinase B (PKB/Akt) and endothelial nitric oxide synthase (eNOS) in the lung tissue were determined with Western blotting; the levels of eNOS and NO were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: The results of HE staining and α-SMA immunofluorescence staining showed that tanshinone IIA effectively inhibited MCT-induced pulmonary artery intimamedia thickening and muscularization of the pulmonary arterioles (P < 0.01). The results of Western blotting showed that treatment with tanshinone IIA significantly increased the phosphorylation levels of PI3K, Akt and eNOS proteins in the lung tissue of PAH rats; ELISA results showed that the levels of eNOS and NO were significantly decreased in the rat models after tanshinone IIA treatment (P < 0.01). CONCLUSION Treatment with tanshinone IIA can improve MCT-induced pulmonary hypertension in rats through the PI3K/Akt-eNOS signaling pathway.
Abietanes ; Animals ; Hypertension, Pulmonary/drug therapy* ; Male ; Monocrotaline/toxicity* ; Nitric Oxide Synthase Type III/therapeutic use* ; Phosphatidylinositol 3-Kinase/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Pulmonary Artery ; Rats ; Rats, Sprague-Dawley ; Signal Transduction