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*

PURPOSE: To investigate the effects of valproic acid on the production of nitric oxide (NO) and expression of endothelial nitric oxide synthase (eNOS) in cultured human trabecular meshwork cells (HTMC). METHODS: Primarily cultured HTMC were exposed to 0.25, 0.5, and 1.0 mM valproic acid for 6, 12, and 24 hours. Expression of eNOS mRNA was assessed with Reverse transcription-polymerase chain reaction, and production of NO was assessed with Griess assay. Cellular survival was assessed with the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: Valproic acid at concentrations of 0.25, 0.5, 1.0 mM did not affect the cellular survival of HTMC significantly after exposure for 24 hours. Valproic acid increased NO production in a dose- and time-dependent manner. Also, valproic acid increased the degree of eNOS mRNA expression in a dose-dependent manner in HTMC. CONCLUSIONS: Valproic acid increases production of NO and expression of eNOS mRNA in HTMC. Thus, valproic acid might increase aqueous outflow through the trabecular meshwork.
Humans ; Nitric Oxide Synthase Type III ; Nitric Oxide Synthase ; Nitric Oxide ; RNA, Messenger ; Trabecular Meshwork ; Valproic Acid

BACKGROUND: Repeated application of whole-body periodic acceleration (WBPA) upregulates endothelial nitric oxide synthase and improves brachial artery endothelial function (BAEF) as assessed by measurement of flow-mediated vasodilatation (FMD). However, the acute effect of a single application of WBPA on BAEF has not been fully characterized. In addition, although a novel semi-automatic vessel chasing system (UNEXEF18G) has now been developed in Japan, the direct comparison of UNEXEF18G with a conventional method for FMD measures has not been conducted even if UNEXEF18G has already been utilized in a relatively large scale study. METHODS: We have developed a novel semi-automatic vessel chasing system (UNEXEF18G) that can measure FMD on-line, identify time to peak vasodilatation (TPV), and determine the area under the vasodilatation curve (AUC). Thus, 45 min of WBPA was applied in 20 healthy volunteers (age, 34 +/- 13 years), and BAEF was measured by UNEXEF18G before and after WBPA. Also, UNEXEF18G measured FMD was compared with those of a conventional FMD measurement method at rest in order to validate a novel UNEXEF18G measured FMD. RESULTS: Single WBPA resulted in a significant increase in FMD (from 6.4 +/- 3.4 to 10.7 +/- 4.3%, p < 0.01), a significant decrease in TPV and a significant increase in AUC. In the validation study for UNEXEF18G, Bland and Altman analysis showed that UNEXEF18G measured FMD was almost identical to those of the conventional method at rest. CONCLUSION: These data suggest the usefulness of a new UNEXEF18G and that single application of WBPA results in acute improvement in BAEF in humans.
Acceleration* ; Area Under Curve ; Brachial Artery ; Humans ; Japan ; Nitric Oxide ; Nitric Oxide Synthase Type III ; Vasodilation*

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

PURPOSE: Nitric oxide synthase(NOS) is an important enzyme in the production of nitric oxide(NO). The constitutive type(cNOS) is expressed in the normal physiologic state, and the inducible type(iNOS) in expressed in the active immune state. cNOS is divided into an endothelial type (eNOS) and a neuronal type(nNOS). eNOS affects blood vessels, while nNOS affects nerve fibers. In the present study, we evaluated the expression of eNOS and nNOS in rat bladders with short-term partial outlet obstructions. We presupposed that NO is responsible for prolonged micturition problems after partial outlet obstruction. MATERIALS AND METHODS: Specific pathogen-free Sprague-Dawley rats weighing 250-300g were used for the study. Individual bladders were obtained from sham-operated control rats(n=5) and from experimental rats at 12 hours and 1, 2, 3, and 7 days after partial urethral obstruction(n=25). eNOS and nNOS were detected using immunochemical staining and analyzed with confocal microscopy and an image analyzer. RESULTS: eNOS and nNOS expression were detected in both the control group and in the group with partial outlet obstruction. The expression of eNOS showed a sharp increase at 3 days after obstruction and returned to normal at 7 days. The expression of nNOS was not significantly different between the two groups. CONCLUSIONS: In this study, we showed that eNOS increases in the rat bladder after partial outlet obstruction. This finding suggests that overproduction of NO may be the result of ischemic injury sustained during partial bladder outlet obstruction.
Animals ; Blood Vessels ; Microscopy, Confocal ; Nerve Fibers ; Neurons ; Nitric Oxide ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type III ; Rats ; Rats, Sprague-Dawley ; Urinary Bladder ; Urination

In order to further investigate the mechanisms of action of berberine (Ber), we assessed the effects of Ber on the mRNA expression of nitric oxide synthases (NOS) in rat corpus cavernosum. After incubation with Ber for 1 or 3 h respectively, the levels of NOS mRNA were examined by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that there were iNOS and eNOS mRNA expressions in rat corpus cavernosum. Ber enhanced eNOS mRNA expression in rat penis, but exhibited no effect on the expression of iNOS mRNA (P > 0.05). The present study indicated that the relaxation of Ber involved the NO-cGMP signal transduction pathway. The enhancing effect of Ber on eNOS mRNA expression might associated with its relaxation of corpus cavernosum.
Berberine/*pharmacology ; Connective Tissue/physiopathology ; Nitric Oxide Synthase/*biosynthesis ; Nitric Oxide Synthase/genetics ; Nitric Oxide Synthase Type I/biosynthesis ; Nitric Oxide Synthase Type I/genetics ; Nitric Oxide Synthase Type III/biosynthesis ; Nitric Oxide Synthase Type III/genetics ; Penile Erection/*physiology ; Penis/*metabolism ; Penis/physiology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics

OBJECTIVE: Nitric oxide has a short half-life and is easily oxidized by nitrite, we can indirectly find out its activity by measuring the nitric oxide synthase in cells. The purpose of this study is to confirm the differences in the expression modes of eNOS in uterine endometrium and myometrium between the patients of uterine leiomyoma and the control group. METHODS: We defined the patient group as perimenopausal women who were diagnosed with uterine leiomyoma and underwent total hysterectomy, and the control group as the women who had no lesions in uterus. All of them were classified into proliferative phase and secretory phase by the Noyes standards and compared by immunohistochemical stain for eNOS. RESULTS: There is no significant differences between the patients of uterine leiomyoma and the control group statistically (endometrium P=0.319, myometrium P=0.264). The expression of eNOS in the vascular endothelial cells of the endometrium did not show significant differences statistically by menstrual cycle (proliferative phage P=0.549, secretory phage P=0.240). The expression of eNOS in the myometrium also did not show significant differences by menstrual cycle or by group statistically (proliferative phage P=0.279, secretory phage P=0.224). CONCLUSIONS: In this study, the expression of endothelial nitric oxide synthase was higher in the patients of uterine leiomyoma than in the control group, and during the secretory phase in menstrual period, but there was no statistical significance. We suppose that we can get statistically significant results if we have many cases of subjects.
Animals ; Bacteriophages ; Endometrium ; Endothelial Cells ; Female ; Half-Life ; Humans ; Hysterectomy ; Leiomyoma ; Menstrual Cycle ; Mice ; Myometrium ; Nitric Oxide ; Nitric Oxide Synthase ; Nitric Oxide Synthase Type III ; Uterus

OBJECTIVE: Our purpose was to compare the expression of endothelial nitric oxide synthase in the placenta and umbilical cord of preeclamptic placenta with that of the normotensive placenta. METHOD: We compared placental endothelial nitric oxide synthase expression in preeclamptic (n=5) with in normal (n=5) pregnancies. Frozen sections of umbilical cords, chorionic plate vessels, and terminal villi were immunostained with a monoclonal endothelial nitric oxide synthase antibody. RESULTS: The age revaled no difference between control (28.1+4.2 years). and study group (26.1+4.7 years). The gestational age was statistically different between control (38.9+1.7 weeks) and study group (34.9+3.5 weeks). The neonatal body weight and placental weight were also statistically different between control (3060+528 g) and study group (2160 417 g). No difference in endothelial nitric oxide synthase immunostaining in the endothelium of the umbilical vessels and stem villous vessels was found between preeclamptic and normotensive pregnancies. In contrast, in the preeclamptic placental endothelial nitric oxide synthase immunostaining was seen in the terminal villous vessels. In the syncytiotrophoblast endothelial niric oxide synthase immunostaining appeared primary basal in location and diffuse in distribution in the preeclamptic placentas but primary apical in the normotensive placentas. CONCLUSION: Differences in endothelial nitric oxide synthase expression in terminal villous vessels and syncytiotrophblast may be a result of vascular alterations or damage that take place in the placenta in preeclampsia.
Body Weight ; Chorion ; Endothelium ; Frozen Sections ; Gestational Age ; Nitric Oxide Synthase Type III ; Nitric Oxide Synthase* ; Nitric Oxide* ; Placenta ; Pre-Eclampsia* ; Pregnancy* ; Trophoblasts ; Umbilical Cord

OBJECTIVES: Cigarette smoking had been recorded as the main cause of impaired endothelium- dependent vasodilation in smokers by reducing nitric oxide (NO), a production of endothelial nitric oxide synthase (eNOS). However, the mechanism of NO impairment via eNOS activity is unclear until now. In this study, cell passage is suggested to be a relevant factor to eNOS expression under cigarette smoking stress. METHODS: Bovine aortic endothelial cells (BAECs) were chosen as the research subject with passages ranking from 6 to 9 (6P to 9P). After exposure of cigarette smoking extract (CSE) solution, MTT assay and Western blot method were performed to check the cell viability as well as eNOS protein concentration. In these experiments, four concentrations of CSE at 0.5, 1, 2, and 4% were selected for treatment. RESULTS: Our results showed that cells almost died at 4% of CSE. Besides, eNOS protein mass had a linear decrease under the increase of CSE concentration. In addition, the effect of CSE on eNOS expression was dissimilar between different passages. CONCLUSIONS: This study indicated that CSE had effect on both cell viability and eNOS expression. Besides, a reduction in protein mass was matched with the decrease of cell viability due to CSE tress. Last but not least, the response of eNOS protein to different concentration of CSE at different passages was disparate, making the hypothesis about cell passage related inhibition of eNOS caused by CSE solution.
Blotting, Western ; Cell Aging* ; Cell Survival ; Endothelial Cells* ; Humans ; Nitric Oxide ; Nitric Oxide Synthase Type III ; Nitric Oxide Synthase* ; Research Subjects ; Smoking* ; Vasodilation

Chronic (>24 h) exposure of arsenite, an environmental toxicant, has shown the decreased nitric oxide (NO) production in endothelial cells (EC) by decreasing endothelial NO synthase (eNOS) expression and/or its phosphorylation at serine 1179 (eNOS-Ser1179 in bovine sequence), which is associated with increased risk of vascular diseases. Here, we investigated the acute (<24 h) effect of arsenite on NO production using bovine aortic EC (BAEC). Arsenite acutely increased the phosphorylation of eNOS-Thr497, but not of eNOS-Ser116 or eNOS-Ser1179, which was accompanied by decreased NO production. The level of eNOS expression was unaltered under this condition. Treatment with arsenite also induced reactive oxygen species (ROS) production, and pretreatment with a ROS scavenger N-acetyl-L-cysteine (NAC) completely reversed the observed effect of arsenite on eNOS-Thr497 phosphorylation. Although protein kinase C (PKC) and protein phosphatase 1 (PP1) were reported to be involved in eNOS-Thr497 phosphorylation, treatment with PKC inhibitor, Ro318425, and overexpression of various PKC isoforms did not affect the arsenite-stimulated eNOS-Thr497 phosphorylation. In contrast, treatment with PP1 inhibitor, calyculin A, mimicked the observed effect of arsenite on eNOS-Thr497 phosphorylation. Lastly, we found decreased cellular PP1 activity in arsenite-treated cells, which was reversed by NAC. Overall, our study demonstrates firstly that arsenite acutely decreases NO production at least in part by increasing eNOS-Thr497 phosphorylation via ROS-PP1 signaling pathway, which provide the molecular mechanism underlying arsenite-induced increase in vascular disease.
Acetylcysteine ; Endothelial Cells ; Nitric Oxide Synthase ; Nitric Oxide Synthase Type III ; Nitric Oxide* ; Phosphorylation ; Protein Isoforms ; Protein Kinase C ; Protein Phosphatase 1 ; Reactive Oxygen Species ; Serine ; Vascular Diseases