The expression of nitric oxide synthase (NOS) isoforms in the ovaries of pigs was examined to study the involvement of nitric oxide, a product of NOS activity, in the function of the ovary. Western blot analysis detected three types of NOS in the ovary, including constitutive neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS); eNOS immunoreactivity was more intense compared with that of iNOS or nNOS. Immunohistochemical studies demonstrated the presence of nNOS and eNOS in the surface epithelium, stroma, oocytes, thecal cells, and endothelial cells of blood vessels. Positive immunoreactions for nNOS and iNOS were detected in the granulosa cells from multilaminar and antral follicles, but not in those of unilaminar follicles. iNOS was detected in the surface epithelium, oocytes, and theca of multilaminar and antral follicles. Taking all of the findings into consideration, the observed differential expression of the three NOS isoforms in the ovary suggests a role for nitric oxide in modulating reproduction in pigs.
Animals ; Blotting, Western/veterinary ; Female ; Immunohistochemistry/veterinary ; Nerve Tissue Proteins/*biosynthesis ; Nitric Oxide/metabolism ; Nitric Oxide Synthase/*biosynthesis ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Ovarian Follicle/*enzymology/growth&development ; Swine/*physiology

Nitric oxide (NO) in general plays a beneficial physiological role as a vasorelaxant and the role of NO is decided by its concentration present in physiological environments. NO either facilitates cancer-promoting characters or act as an anti-cancer agent. The dilemma in this regard still remains unanswered. This review summarizes the recent information on NO and its role in carcinogenesis and tumor progression, as well as dietary chemopreventive agents which have NO-modulating properties with safe cytotoxic profile. Understanding the molecular mechanisms and cross-talk modulating NO effect by these chemopreventive agents can allow us to develop better therapeutic strategies for cancer treatment.
Carcinogenesis ; Chemoprevention* ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Nitric Oxide*

To elucidate the role of nitric oxide synthase (NOS) in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), we analyzed the expression of constitutive neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) in the spinal cords of rats with EAE. We further examined the structural interaction between apoptotic cells and spinal cord cells including neurons and astrocytes, which are potent cell types of nitric oxide (NO) production in the brain. Western blot analysis showed that three forms of NOS significantly increased in the spinal cords of rats at the peak stage of EAE, while small amounts of these enzymes were identified in the spinal cords of rats without EAE. Immunohistochemical study showed that the expression of either nNOS or eNOS increased in the brain cells including neurons and astrocytes during the peak and recovery stages of EAE, while the expression of iNOS was found mainly in the inflammatory macrophages in the perivascular EAE lesions. Double labeling showed that apoptotic cells had intimate contacts with either neurons or astrocytes, which are major cell types to express nNOS and eNOS constitutively. Our results suggest that the three NOS may play an important role in the recovery of EAE.
Animals ; Apoptosis ; Encephalomyelitis, Autoimmune, Experimental/*enzymology ; Endothelium, Vascular/enzymology ; Immunohistochemistry ; In Situ Nick-End Labeling ; Male ; Nitric Oxide Synthase/*metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Rats ; Rats, Inbred Lew ; Spinal Cord/*enzymology/pathology

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

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

The role of nitric oxide (NO) in the ocular surface remains unknown. We investigated the conditions leading to an increase of NO generation in tear and the main sources of NO in ocular surface tissue. We evaluated the dual action (cell survival or cell death) of NO depending on its amount. We measured the concentration of nitrite plus nitrate in the tears of ocular surface diseases and examined the main source of nitric oxide synthase (NOS). When cultured human corneal fibroblast were treated with NO producing donor with or without serum, the viabilities of cells was studied. We found that the main sources of NO in ocular surface tissue were corneal epithelium, fibroblast, endothelium, and inflammatory cells. Three forms of NOS (eNOS, bNOS, and iNOS) were expressed in experimentally induced inflammation. In the fibroblast culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblast cells caused by serum deprivation in a dose dependent manner up to 500 micrometer SNAP, but a higher dose decreased cell viability. This study suggested that NO might act as a doubleedged sword in ocular surface diseases depending on the degree of inflammation related with NO concentration.
Animals ; Apoptosis/drug effects/physiology ; Aqueous Humor/metabolism ; Blood Proteins/pharmacology ; Cell Survival/drug effects/physiology ; Cells, Cultured ; Epithelium, Corneal/*cytology/*enzymology ; Fibroblasts/cytology/enzymology ; Humans ; Nitric Oxide/biosynthesis/*physiology ; Nitric Oxide Donors/pharmacology ; Nitric Oxide Synthase/metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Penicillamine/*analogs & derivatives/pharmacology ; Peroxynitrous Acid/biosynthesis ; Rabbits ; Tears/metabolism ; Uveitis/metabolism

OBJECTIVETo investigate the effects of salvia miltiorrhiza injection (SM) on gentamicin (GM)-induced expression of nitric oxide synthase (NOS) isoforms in guinea pig cochlea, and to explore the protective mechanism of SM on GM-induced ototoxicity.

METHODS40 guinea pigs were randomly assigned to 4 groups: control group, GM group, SM group and GM plus SM group. Expression of NOS isoforms in the guinea pig cochlea was detected by the SABC method of immunohistochemistry and microscope image analysis technique. Auditory threshold was tested by auditory brainstem response (ABR) measurement.

RESULTSInducible NOS (iNOS/NOS II) expression and ABR threshold in GM plus SM group were both significantly declined as compared with those in GM group (P < 0.01). Moreover, change of iNOS expression was in high correlation with that of ABR threshold ([r] > 0.7, P < 0.01). While expression of neuronal NOS (nNOS/NOS I) and endothelial NOS (eNOS / NOS III) showed no significant differences in all groups.

CONCLUSIONSM had no effect on the expression of nNOS and eNOS, but could inhibit iNOS high-expression induced by GM to reduce excessive generation of NO, therefore SM could protect against GM ototoxicity.

Animals ; Cochlea ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Female ; Gentamicins ; toxicity ; Guinea Pigs ; Male ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type I ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Protective Agents ; pharmacology ; Salvia miltiorrhiza ; chemistry

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

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

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