• Biomolecules & Therapeutics
• /
• v.8 no.4
• /
• pp.325-331
• /
• 2000

The present study was designed to assess the role of spinal adenosine $A_2$ receptor in the regulation of cardiovascular functions such as mean arterial pressure (MAP) and heart rate (HR) in male Sprague-Dawley rats. Rats (250~300 g) were anesthetized with urethane and paralyzed with d-tubocurarine and artificially ventilated. blood pressure and HR were continuously monitored via a femoral catheter connected to a pressure transducer and a polygraph. Drugs were administered intrathecally using injection cannula through guide cannula which was inserted inthrathecally at lower thoracic level through a puncture of an atlantooccipital mombrane. Intrathecal injection of an adenosine $A_2$ receptor agonist, 5'-(N-cyclopropyl)-carboxamaidoadenosine (CPCA; 1, 2 and 3 nmol, respectively), produced a dose-dependent decrease in MAP and HR. Pretreatment with $N^{G}$-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor or 10 nmol of MDL-12,330, an adenylate cyclase inhibitor blocked significantly the depressor and bradycardic effect of 2 nmol of CPCA. But, Pretreatment with 3 nmol of bicuculline, gamma-aminobutyric acid A (GAB $A_{A}$) receptor antagonist, or 50 nmol of 5-aminovaleric acid, GAB $A_{B}$ receptor antagonist did not inhibit the depressor and bradycardic effect of 2 nmol of CPCA. These results indicate that adenosine $A_2$ receptor in the spinal cord plays an inhibitory role in the regulation of cardiovascular function and that the depressor and bradycardic action of adonosine $A_2$ receptor are mediated via the synthesis of nitric oxide and the activation of adenylate cyclase in the spinal cord of rats.s.s.s.

• Korean Journal of Veterinary Research
• /
• v.51 no.3
• /
• pp.185-191
• /
• 2011

Trimethyltin chloride (TMT) has been used as a neurotoxin for inducing brain dysfunction and neuronal death. Neuronal death in the hippocampus by TMT may generate excessive nitric oxide, but there are few studies about nitric oxide synthase enzyme involved in the synthesis of nitric oxide. The purpose of present study is to analyze the TMT toxicity in each region of rat hippocampus. To evaluate the involvement of nitric oxide, we analyzed the effects of aminoguanidine known as a selective inhibitor for inducible nitric oxide synthase on behavioral changes and the hippocampus of rat by TMT toxicity. 6-week-old male Sprague-Dawley rats were administered with a single dose of TMT (8 mg/kg b.w., i.p.) and the control group was similarly administered with distilled water. TMT + aminoguanidine-treated groups were administered with aminoguanidine (10 mg/kg or 100 mg/kg b.w., i.p.) for 3 days prior to TMT injection. The rats were sacrificed 2 days after TMT administration. In the TMT-treated group, a number of cell losses were seen in CA1, CA3 and the dentate gyrus. In the TMT + aminoguanidine-treated group, neuronal death was seen in CA1 and CA3, but reduced in the dentate gyrus compared to the TMT-treated group. Western blot analysis showed that cleaved caspase-3 expression was increased in the TMT-treated group compared to the control group. However, the expression significantly declined in the TMT + aminoguanidine-treated group. The present findings suggest that inducible nitric oxide synthase is involved in neuronal death induced by TMT.

• Journal of Periodontal and Implant Science
• /
• v.27 no.4
• /
• pp.883-908
• /
• 1997

Bone remodeling is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. The process is tightly regualted at the local level by an incompletely known netwotk of peptide and non-peptide fators. Nitric oxide(NO), synthesized by nitric oxide synthetase(NOS) from L-arginine, is becoming recognized as an important bioregualtory molecule in a variety of tissue, but little is known about its possible role in periodontal tissue. The purpose of this study is to investigate the expression of nitric oxide synthetase(NOS) in inflamed gingiva and the effects of cytokine on the expression of NOS protein. The expression of NOS in gingival tissue was evaluated by immunohistochemical staining for $NOS_1$, $NOS_2$, $NOS_3$. The effect of cytokine on the expression of NOS in human periodontal ligament cells and osteoblast-like HOS cells by western blot analysis. Further, we studied that NO functions in periodontal ligament cells as a regulatory molecule. PDL cells incubated with NOS inhibitor and donor. The protein expression, type I collagen & non-collagenous protein, nitrate production and cell proliferation were evaluated The results were as follows. 1. $NOS_1$, $NOS_2$, $NOS_3$ was rarely distributed in healthy gingiva, but stronger stained in gingival epithelium, endothelial cells, and mononuclear cells of inflammed gingiva. 2. The cytokine stimulated $NOS_1$, and $NOS_3$ protein were not inducing or inhibitory effect to compared with control in PDL and HOS cells. 3.Incubation of cells with combination of $TNF-{\alpha}$, $IFN-{\gamma}$, LPS result in a time dependant increase in $NOS_2$ expression, reaching a maximal level after 24 hours of stimulation. 4. The osteonectin protein inhibitory effect of NMA, inhibitor of NOS, was reversed by Larginine in dose dependant manner. 5. NMA decreased cell poliferation and nitrate production, but the inhibitory efffect of NMA was also prevented by the NO donor, sodium nitropruiside. These results suggest that exogenously synthesized NO was playing a stimulating effect on cell proliferation or on non-collagenous protein expression. Therefore NO have an important role in mediation of localized bone destruction associated inflammatory bone disease such as periodontitis.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1997.04a
• /
• pp.91-91
• /
• 1997

흰쥐의 뒷발바닥에 carragennan(cg)을 피하투여하여 염증성 통증을 유발한 뒤, 그 통증이 최고에 달하는 3시간 뒤 Ach이나 SNP를 동일한 항법으로 투여해서 30분 후 cg유발 통증에 대하여 그 효과를 Randall-Selitto paw pressure test로 검색하였고, 체내 Nitric Oxide Synthase(NOS) 억제제인 L-NAME과 L-NOARG를 용량별로 적용하여 Ach의 진통효과를 억제하는 정도와 Methylene Blue 및 Hemoglobin을 투여해서 SUP효과 억제를 검사하였다. 그리고 척수 지주막하강내로 catheter를 삽입하여 위의 NO donor를 주입하고, NO의 중추신경계에서의 통각전도에 미치는 효과를 Tail-Flick test로 살펴보았다. 끝으로 NO가 가진 급,만성 통각관련효과를 희석한 formalin을 써서 검색하였다. 결 과: Ach과 SNP는 흰쥐에게 말초경로투여시 유의성있는 진통효과를 보였으며, NOS inhibitor와 NO scavenger로 그 효과가 역전되었다. 또한 NOS inhibitor간에는 억제효과가 용량의존성이 유사하게 나타났고, 중추신경계로의 직접투여때는 여러 생리적 조건이 직, 간접으로 관여함이 확인되었다.

• Archives of Pharmacal Research
• /
• v.23 no.1
• /
• pp.54-58
• /
• 2000

To elucidate the molecular mechanisms for the suppression of LPS-induced nitric oxide (NO) production by a dehydrocostus lactone (DL) from Saussurea lappa, we examined the preventive effect of this compound on $NF-{\kappa}B$ activation in LPS-treated RAW 264.7 macrophages and U937 human monocytic cells. The results suggest that the suppression of NO production is mediated by the inhibitory action on the i-NOS gene expression through the inactivation of $NF-{\kappa}B$ and this sesquiterpene lactone can act as a pharmacological inhibitor of the $NF-{\kappa}B$ activation.

• Natural Product Sciences
• /
• v.11 no.2
• /
• pp.85-88
• /
• 2005

The methanolic extract from the seeds of Arctium lappa was found to inhibit the LPS-induced nitric oxide (NO) production in murine macrophage RAW264.7 cells. Bioassay-guided fractionation of a methylene chloride soluble fraction led to the isolation of three lignan compounds, arctiin (1), arctigenin (2), and lappaol B (3). Their structures were elucidated by UV, IR, MS, and NMR data, as well as by comparison with those of the literatures. Arctigenin (2) and lappaol B (3) had an iNOS inhibitory activity with $IC_{50}$ values of 12.5 and $25.9\;{\mu}M$, respectively.

• Animal cells and systems
• /
• v.4 no.2
• /
• pp.151-155
• /
• 2000

Nitric oxide (NO) is a reactive free radical which plays important roles in animal physiology. To investigate involvement of NO in acrosome reaction (AR), effects of drugs which modulate the intracellular NO level were examined in mouse spermatozoa. N (G)-nitro-L-arginine (L-NA), a potent inhibitor of NO synthesis, decreased AR in a reversible manner, On the other hand, sodium nitroprusside (SNP), an NO generating agent, increased spontaneous AR. Preincubation of sperm in the presence of L-NA potentiated AR after sperm transfer into plain- or SNP-media. Methylene blue, a NO scavenging agent, decreased spontaneous AR. Taken together, it is concluded that NO positively controls AR.

• Archives of Pharmacal Research
• /
• v.22 no.4
• /
• pp.410-413
• /
• 1999

In bioassay-guided search for inducible nitric oxide synthase (iNOS) inhibitory compounds from higher plants of South Korea, two $\beta$-carboline (2) have been isolated form the cortex of Melia azedarach var. japonica. The structures of these compounds were elucidated on the basis of spectroscopic data. Compounds 1 to 2 showed marked inhibitory activity of iNOS on LPS-and interferon-${\gamma}$-stimulated RAW 264.7 cells.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.3
• /
• pp.908-913
• /
• 2004

Farfrae Flos has been clinically used for the treatment of asthma in traditional oriental medicine. There is lack of studies regarding the effects of Farfrae Flos on the immunological activities. The present study was conducted to evaluate the effect of Farfrae Flos on the regulatory mechanism of cytokines and nitric oxide (NO) for the immunological activities in Raw 264.7 cells. In Raw 264.7 cells stimulated with lipopolysaccharide (LPS) to mimic inflammation, Farfrae Flos water extract inhibited nitric oxide production in a dose-dependent manner and abrogated inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2). Farfrae Flos water extract did not affect on cell viability. To investigate the mechanism by which Farfrae Flos water extract inhibits iNOS and COX-2 gene expression, we examined the on the phospholylation of inhibitor κBα and production of TNF-α, IL-1β and IL-6. Results provided evidence that Farfrae Flos inhibited the production of interleukin-1β (IL-1β) and the activation of phospholylation of inhibitor κBα in Raw 264.7 cells activated with LPS. These findings suggest that Farfrae Flos can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

• Preventive Nutrition and Food Science
• /
• v.12 no.2
• /
• pp.74-78
• /
• 2007

Fucoidan, that is high-molecular-weight sulfated polysaccharides extracted from brown seaweeds has been shown to elicit various biological activities. Here, we investigated the effects of fucoidan on cell proliferation and nitric oxide (NO) production in neuronal blastoma cell (SH-SY5Y). In the present study, we demonstrated that fucoidan treatment resulted in increase of cell proliferation and NO production. When cells were treated with amyloid-${\beta}$ (A${\beta}$) in the absence or presence of fucoidan, fucoidan recovered the cell viability decreased by A${\beta}$ peptides. To further determine whether nitric oxide synthase (NOS) is involved in proliferative effect of fucoidan, cells were treated with NOS inhibitors in the absence or presence of fucoidan. Selective constitutive nitric oxide synthase (cNOS) inhibitor, diphenylene iodonium chloride (DPI), caused a decrease of cell viability, whereas cell viability was increased by specific inducible nitric oxide synthase (iNOS) inhibitor, S-methylisothiourea (SMT), in the fucoidan-untreated cells. Treatment with fucoidan inhibited the cell viability decreased in DPI-exposed cells. In contrast, fucoidan had no effect on cell growth in SMT-treated cells, indicating that cNOS may not play a role in the proliferation of fucoidan-treated cells. The present data suggest that fucoidan has proliferative and neuroprotective effects and these effects may be associated with iNOS.