OBJECTIVETo study the effects of insulin-like growth factor II (IGF-II) on regulating the levels of nitric oxide (NO) and the mRNA transcriptions of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) in mouse osteoblast-like cells.

METHODSMouse osteoblastic cell line MC3T3-E1 was selected as the effective cell of IGF-II. After the cells were treated with IGF-II at different concentrations for different intervals of time, MTT colorimetry was used for examining the cell proliferation. Nitrate reductase method was applied for detecting the NO concentrations in cell culture supernatants and RT-PCR employed for determining the levels of cellular iNOS and eNOS mRNAs.

RESULTSAfter the MC3T3-E1 cells were treated with IGF-II at the dosages of 1 microg/L for 72 h, 10 and 100 microg/L for 24, 48 and 72 h respectively, all the MTT values increased markedly (P < 0.05 or P < 0.01). After the cells were treated for 48 and 72 h at the dosage of 100 microg/L IGF-II respectively, the levels of NO in the supernatants of cell cultures and cellular iNOS mRNA decreased significantly (P < 0.01). However, the levels of eNOS mRNA in the cells treated with any of the IGF-II dosages for the different times were stable (P > 0.05).

CONCLUSIONSIGF-II at the dosages of 1 approximately 100 microg/L showed the effects on promoting proliferation, which as probably due to the maintenance of low NO levels. Inducible NOS gene expression at the level of transcription was down regulated in the MC3T3-E1 cell treated with higher dosage of IGF-II (100 microg/L) but eNOS mRNA was not, which might be one of the mechanisms for the maintenance of low NO levels.

3T3 Cells ; Animals ; Insulin-Like Growth Factor II ; pharmacology ; Mice ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; biosynthesis ; genetics ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Osteoblasts ; cytology ; drug effects ; enzymology ; RNA, Messenger ; biosynthesis

BACKGROUNDExposure of adult mice to more than 95% O(2) produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS.

METHODSOne hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages > 95% oxygen or room air for 24- 72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24, 48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues.

RESULTSOPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85 +/- 0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31 +/- 0.92 in the WT group (P < 0.05). iNOS mRNA (48 hours: 1.04 +/- 0.08 vs. 0.63 +/- 0.09, P < 0.01; 72 hours: 0.89 +/- 0.08 vs. 0.72 +/- 0.09, P < 0.05) and eNOS mRNA (48 hours: 0.62 +/- 0.08 vs. 0.43 +/- 0.09, P < 0.05; 72 hours: 0.67 +/- 0.08 vs. 0.45 +/- 0.09, P < 0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54 +/- 3.18 vs. 12.52 +/- 2.46, P < 0.05) and eNOS (19.83 +/- 5.64 vs. 9.45 +/- 3.82, P < 0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia.

CONCLUSIONOPN can protect against hyperoxia-induced lung injury by inhibiting NOS.

Animals ; Hyperoxia ; genetics ; physiopathology ; Immunohistochemistry ; Lung ; metabolism ; Lung Injury ; etiology ; genetics ; metabolism ; Mice ; Mice, Knockout ; Nitric Oxide Synthase ; genetics ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; Nitric Oxide Synthase Type III ; genetics ; Osteopontin ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVESTo investigate the cause of spermatogenic cells decreasing after spinal cord injury.

METHODSImmunohistochemical S-P method was used to detect the expression of iNOS and Bcl-2 protein in the testis of spinal cord injured and sham-operated adult rats in second week and fourth week after operation.

RESULTSSecond week and fourth week after operation, the expression of iNOS of operated rats increased significantly (P < 0.05). Fourth week after operation, the number of Bcl-2 positive cells in spinal cord injured group decreased significantly (P < 0.05).

CONCLUSIONSThe expression veition of iNOS and Bcl-2 is the cause that inducing the decrease of spermatogenic cells in testis of spinal cord injured rats.

Animals ; Male ; Nitric Oxide Synthase ; biosynthesis ; genetics ; Nitric Oxide Synthase Type II ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; metabolism

AIMTo observe the direct effect of urotensin II (U II) on the release of nitric oxide (NO) and expression of inducible nitric oxide synthase (iNOS) mRNA in human umbilical vein endothelial cells (HUVEC).

METHODSHUVEC were cultured with different concentrations of U II (10(-9)-10(-7) mol/L) for 24 hours. Then the supernatant was collected to detect the level of NO and the activity of iNOS, the expression of iNOS mRNA of HUVEC was measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULTSIn comparison with controls, the level of NO, the activity of iNOS and the iNOS mRNA expression increased significantly (P < 0.05).

CONCLUSIONU II may up-regulate the expression of iNOS mRNA and increase NO generation in HUVEC, it suggests that U II may relax blood vessel by activating iNOS/NO pathway.

Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; RNA, Messenger ; genetics ; Urotensins ; pharmacology

BACKGROUNDHigh levels of nitric oxide (NO) produced by inducible NO synthase (iNOS) have been associated with atherosclerosis processes. Naoxintong is a traditional Chinese medicine for treatment of cerebrovascular and cardiovascular disease. The aim of the present study was to detect and quantify changes of iNOS mRNA and NO levels in the vessel wall after the administration of Naoxintong in an atherosclerotic rabbit model.

METHODSForty New Zealand white rabbits were randomly divided into five groups (n = 8). Rabbits were fed a standard diet (group A), an atherogenic diet consisting of 79% standard feed + 1% cholesterol + 5% lard + 15% egg yolk powder (group B), an atherogenic diet with Naoxintong 0.25 mg×kg(-1)×d(-1) (group C), an atherogenic diet with Naoxintong 0.5 mg×kg(-1)×d(-1) (group D), or atherogenic diet with Naoxintong 1.0 mg×kg(-1)×d(-1) (group E) for 12 weeks.

RESULTSSupplemented administration of Naoxintong led to a down-regulation of cholesterol (CHOL) (P < 0.001) and low-density lipoprotein (LDL) (P < 0.001). The trend became more notable as the dose of Naoxintong increased; group C vs. group B (CHOL, P = 0.568; LDL-cholesterol (LDL-C), P = 0.119), group D vs. group B (CHOL, P = 0.264; LDL-C, P = 0.027), group E vs. group B (CHOL, P = 0.028; LDL-C, P = 0.002). Atherosclerotic lesions in aorta were reduced in Naoxintong groups (groups C, D, E) compared to group B. Group B had higher iNOS mRNA (P = 0.001) and NO level (P < 0.001) than group A. Compared with the atherogenic diet fed-rabbits, Naoxintong supplements decreased the expression of iNOS mRNA (P < 0.001) and the NO level (P < 0.001) in the vessel wall. Groups given a higher Naoxintong dose exhibited greater benefits. iNOS mRNA and NO levels seemed to be reduced in group C, although the difference did not quite reach statistical significance (iNOS mRNA, P = 0.130; NO, P = 0.038). iNOS mRNA and NO levels significantly decreased in group D (iNOS mRNA, P = 0.019; NO, P = 0.018) and group E (iNOS mRNA, P = 0.004; NO, P < 0.001).

CONCLUSIONNaoxintong has beneficial effects on atherosclerosis treatment by reducing expression of iNOS mRNA and the NO level in the vessel wall.

Animals ; Atherosclerosis ; drug therapy ; enzymology ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Rabbits

OBJECTIVETo investigate the gene and protein expressions of three isoforms of nitric oxide synthase (NOS) and gene expression of Caspase-3, and effect of dexamethasone on them in neonatal rats with lipopolysaccharide (LPS)-induced endotoxemic brain damage.

METHODSExpressions of the three isoforms of NOS and caspase-3 mRNA in the brain were investigated by RT-PCR in postnatal 7-day Wistar rats with acute endotoxemia by intraperitoneal administration of LPS. Regional distributions of NOSs were examined by immunohistochemical technique.

RESULTSnNOS and Caspase-3 mRNA were obviously detected. eNOS mRNA was faintly expressed, but iNOS mRNA was undetectable in the control rat brain. The expressions of NOS mRNA of three isoforms were weak 2 h after LPS (5 mg/mg) delivery, peaked at 6 h, and thereafter, reduced gradually up to 24 h. The expression intensity was in the order of nNOS> iNOS> eNOS. Widespread nNOS, scattered eNOS distribution and negative iNOS were identified in the control rat brain and all isoforms of NOS could be induced by LPS which reached the apex at 24 h in the order of nNOS> iNOS> eNOS as detected by immunostaining. Although Caspase-3 mRNA could be found in all groups, DNA fragmentation was only seen at 6 h and 24 h. The expressions of NOS and Caspase-3 mRNA were inhibited in the rat brain when dexamethasone was administrated.

CONCLUSIONLPS-induced NO production induces apoptosis of neurons through mechanism involving the Caspase-3 activation, which may play an important role in the pathogenesis of brain damage during endotoxemia, and neuro-protective effects of dexamethasone may be partially realized by inhibiting the expression of NOS mRNA.

Animals ; Animals, Newborn ; Apoptosis ; Brain ; drug effects ; enzymology ; Caspase 3 ; Caspases ; genetics ; metabolism ; Dexamethasone ; pharmacology ; Disease Models, Animal ; Endotoxemia ; chemically induced ; enzymology ; Female ; Lipopolysaccharides ; Male ; Nerve Tissue Proteins ; genetics ; metabolism ; Nitric Oxide Synthase ; genetics ; metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction

Brain hypoxia-ischemia has been considered as critical factors in many human central nervous system diseases, including stroke and neonatal hypoxic-ischemic encephalopathy. In brain hypoxia-ischemia processes, inducible NO synthase (iNOS) is induced to produce excessive nitric oxide (NO) which leads to cascade reactions of inflammation and neuronal death, deteriorating primary brain injury. Inhibiting iNOS expression has opened new perspectives in the treatment of brain hypoxia-ischemia because iNOS inhibitor has been shown as a potent therapeutic agent. This reviews focus on recent research achievements regarding the relationship between iNOS and ischemic-hypoxic brain damage and the perspective of using iNOS inhibitors as therapeutic strategies for brain ischemic-hypoxic brain damage.
Animals ; Humans ; Hypoxia-Ischemia, Brain ; drug therapy ; metabolism ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; genetics ; physiology

OBJECTIVETo investigate gene expression of three nitric oxide synthase isozymes in injured spinal cord tissue.

METHODSThirty-six adult SD rats were randomly divided into six groups: a normal group and five injury groups, with six per each group. Animals in the injury groups were sacrificed at 2, 6, 12, 24, 48 h after injury. A compression injury model on the spinal cord was made according to Nystrom B et al and gene expression of the three NOS isozymes were examined by reverse transcription polymerase chain reaction (RT-PCR).

RESULTSGene expression of nNOS and eNOS were detectable in the normal group and were up-regulated quickly after injury, reaching a maximum at 6 h: (0.633 +/- 0.012) and (1.236 +/- 0.207). Gene expression of iNOS was detectable only in the injury groups and it was gradually up-regulated after injury, reaching a maximum at 24 h: (1.043 +/- 0.049).

CONCLUSIONInjury to the spinal cord leads to early up-regulation of cNOS and late up-regulation of iNOS. Different NOS isozymes may play different roles in secondary spinal cord injury.

Animals ; Female ; Gene Expression Regulation, Enzymologic ; Male ; Nitric Oxide Synthase ; genetics ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; RNA ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Spinal Cord ; enzymology ; pathology ; Spinal Cord Injuries ; enzymology ; genetics

AIMTo investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats.

METHODSThirty-two adult male Wistar rats were randomly divided into one sham-operated group (A) and three castrated groups (B, C and D). One week after surgery, rats were treated with normal saline (groups A and B) or oral icariin (1 mg/[kg.day] for group C and 5 mg/[kg.day] for group D) for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure (ICP) during electrostimulation of the cavernosal nerve. The serum testosterone (ST) levels, the percent of smooth muscle (PSM) in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and phosphodiesterase V (PDE5) in corpus cavernosum (CC) were also evaluated.

RESULTSICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A (P 0.01). However, ICP, PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B (P 0.05). Changes in ST and the expression of eNOS and PDE5 were not significant (P 0.05) in groups C and D compared with those in group B.

CONCLUSIONOral treatment with icariin ( 98.6 % purity) for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.

3',5'-Cyclic-GMP Phosphodiesterases ; genetics ; metabolism ; Animals ; Blood Pressure ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; Drugs, Chinese Herbal ; pharmacology ; Erectile Dysfunction ; drug therapy ; metabolism ; Flavonoids ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Male ; Muscle, Smooth ; drug effects ; physiology ; Nitric Oxide Synthase ; genetics ; metabolism ; Nitric Oxide Synthase Type I ; genetics ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Orchiectomy ; Penile Erection ; drug effects ; Penis ; drug effects ; enzymology ; Pressure ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Testosterone ; blood

OBJECTIVETo analyze the expression of inducible nitric oxide synthase (iNOS) in the testis tissues of Fmr1 (fragile X mental retardation 1) knockout and wild-type male mice in different developmental stages, and provide background information for researches on fragile X syndrome.

METHODSThis study included 4, 6, 8 and 10 weeks old Fmr1 knockout and wild-type male mice, 6 in each age group. We identified the genotype of the mice by PCR, and detected and compared the expression of iNOS in the testis tissues of the Fmr1 knockout and wild-type mice by immunohistochemistry.

RESULTSThe iNOS expression was weakly positive in the Leydig cells of the 4-week-old mice, moderately positive in the 6-week-old ones, and strongly positive in 8- and 10-week-old ones, significantly weaker in the Fmr1 knockout than in the wild-type ones.

CONCLUSIONThe expression of iNOS significantly decreases in the testis of Fmr1 knockout mice, suggesting that iNOS may be involved in the pathogenesis of fragile X syndrome.

Animals ; Fragile X Mental Retardation Protein ; genetics ; Fragile X Syndrome ; genetics ; Gene Expression Regulation, Developmental ; Male ; Mice ; Mice, Knockout ; Nitric Oxide Synthase Type II ; metabolism ; Testis ; metabolism