• BMB Reports
• /
• v.35 no.1
• /
• pp.116-126
• /
• 2002

Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.

• Restorative Dentistry and Endodontics
• /
• v.27 no.5
• /
• pp.543-551
• /
• 2002

Nitric oxide (NO) is a small molecule (mol. wt. 30 Da) and oxidative free radical. It is uncharged and can therefore diffuse freely within and between cells across membrane. Such characteristics make it a biologically important messenger in physiologic processes such as neurotransmission and the control of vascular tone. NO is also highly toxic and is known to acts as a mediator of cytotoxicity during host defense. NO is synthesized by nitric oxide synthase (NOS) through L-arginine/nitric oxide pathway which is a dioxygenation process. NO synthesis involves several participants, three co-substrates, five electrons, five co-factors and two prosthetic groups. Under normal condition, low levels of NO are synthesized by type I and III NOS for a short period of time and mediates many physiologic processes. Under condition of oxidant stress, high levels of NO are synthesized by type II NOS and inhibits a variety of metabolic processes and can also cause direct damage to DNA. Such interaction result in cytostasis, energy depletion and ultimately cell death. NO has the potential to interact with a variety of intercellular targets producing diverse array of metabolic effects. It is known that NO is involved in hemodynamic regulation, neurogenic inflammation, re-innervation, management of dentin hypersensitivity on teeth. Under basal condition of pulpal blood flow, NO provides constant vasodilator tone acting against sympathetic vasoconstriction. Substance P, a well known vasodilator, was reported to be mediated partly by NO, while calcitonin-gene related peptide has provided no evidence of its relation with NO. This review describes the roles of NO in dental pulp in addition to the known general roles of it.

• Journal of Ginseng Research
• /
• v.40 no.3
• /
• pp.285-291
• /
• 2016

Background: Ginsenosides have been shown to exert beneficial pharmacological effects on the central nervous, cardiovascular, and endocrine systems. We sought to determine whether total ginsenosides (TG) inhibit monocrotaline (MCT)-induced pulmonary hypertension and to elucidate the underlying mechanism. Methods: MCT-intoxicated rats were treated with gradient doses of TG, with or without $N^G$-nitro-$\small{L}$-arginine methyl ester. The levels of molecules involving the regulation of nitric oxide and mitogen-activated protein kinase pathways were determined. Results: TG ameliorated MCT-induced pulmonary hypertension in a dose-dependent manner, as assessed by the right ventricular systolic pressure, the right ventricular hypertrophy index, and pulmonary arterial remodeling. Furthermore, TG increased the levels of pulmonary nitric oxide, endothelial nitric oxide synthase, and cyclic guanosine monophosphate. Lastly, TG increased mitogen-activated protein kinase phosphatase-1 expression and promoted the dephosphorylation of extracellular signal-regulated protein kinases 1/2, p38 mitogen-activated protein kinase, and c-Jun NH2-terminal kinase 1/2. Conclusion: TG attenuates MCT-induced pulmonary hypertension, which may involve in part the regulation of nitric oxide and mitogen-activated protein kinase pathways.

• Journal of Veterinary Clinics
• /
• v.22 no.3
• /
• pp.220-227
• /
• 2005

Although ketamine has been used in the field of anesthetic medicine for its safety and favourable respiratory effects, the cardiovascular effects of ketamine is still controversial. To clarify the action and mechanism of ketamine upon cardiovascular system, arterial blood pressure, tension of aortic ring, left ventricular developed pressure and heart rate were measured in rats, Ketamine produced two types of effects on arterial blood pressure in anesthetized rats; monophasic effect (blood pressure lowering) and biphasic effect (initial transient blood pressure increasing following sustained lowering), The ketamine-induced lowering of aterial blood pressure showed a concentration-dependent manner, inhibited by the pretreament of $MgCl_2$ and potentiated by the pretreatment of $CaCl_2$. The ketamine-induced lowering of aterial blood pressure was suppressed by the pretreatment of nifedipine, verapamil or lidocaine. In phenylephrine-precontracted endothelium intact (+E) aortic rings, ketamine sometimes caused a small enhancement of contraction ($112.5{\pm}3.6{\%}$). However, in many experiments, ketamine produced a concentration-dependent relaxation in +E aortic rings precontracted with either phenylephrine or KCl. Ketamine-induced relaxation was significantly greater in KCl-precontracted strips than phenylephrine-precontracted strips. In phenylephrine-precontracted +E aortic rings, the ketamine-induced vasorelaxation was not suppressed by endothelium removal or by the pretreatment of a nitric oxide synthase inhibitors, L-$N^G$-nitro-arginine and a guanylate cyclase inhibitors, methylene blue, suggesting that the ketamine-induced vasorelaxation is not dependent on the endothelial function. In addition, ketamine elicited an increase in left ventricular developed pressure in perfused hearts accompanied by decrease in heart rate. These results suggest that ketamine could evoke a hypotension due to vasorelaxation and decrease in heart rate in rats. The inhibitory effect of cardiovascular system might be associated with modulation of $Ca^{2+}$ homeostasis.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.25 no.4
• /
• pp.282-290
• /
• 1992

Based on surplus production models using fishery data for the last 20 years, a stock assessment was conducted for the small yellow croaker in Korean waters. The maximum sustainable yields (MSY) from the Schaefer and Fox models were estimated to be 37,000 metric tons (mt) and 33,450 mt. Zhang's model using time-series biomass with instantaneous coefficients of fishing mortality (F) and using time-series biomass and catch yielded MSY estimates of 45,328 mt and 40,160 mt, respectively. A yield-per-recruit analysis showed that the current yield per recruit of about 20g with F= 1.11 $yr^{-l}$, where the age at first capture $(t_c)$ is 0.604, was much lower than the maximum possible yield per recruit of 43g. Fixing $t_c$ at the current level and reducing fishing intensity (F) from 1.11 $yr^{-l}$ to 0.4 $yr^{-l}$ yielded only a small increase in predicted yield per recruit, from 20 to 25g. However, estimated yield per recruit increased to 43g by increasing $(t_c)$ from the current age (0.604) to age three with F fixed at the current level. This age at first capture corresponded to the optimal length which was obtained from the $F_{0.1}$ method. According to the analysis of stock recovery strategies employing the Zhang model, the optimum equilibrium biomass $(B^*_{MSY})$ which produces the maximum yield could be achieved after approximately five years at the lower fishing intensity (F=0.5).

• Food Science and Preservation
• /
• v.16 no.5
• /
• pp.705-713
• /
• 2009

We prepared salmon patties and compared the quality characteristics thereof with those of commercial tuna and pork patties. The moisture and crude ash contents of salmon patty were lower, whereas the crude protein content was higher, than those of commercial patties. The crude lipid content of salmon patty was higher than that of tuna patty, but lower than that of pork patty. The pH value and the volatile basic nitrogen content of salmon patty were lower than those of the commercial patties. Hunter color values (L, a, b) in a cross-section of cooked salmon patty were higher, whereas the ${\Delta}E$ value was lower, than those of the two commercial patties. The lipophilic browning index (0.397) of salmon patty was higher, whereas the hydrophilic browning index (0.047) was lower, than those of commercial patties. Trichloroacetic acid-soluble N content (272 mg/100 g) of salmon patty was lower than of commercial patties. The major fatty acids of salmon patty were palmitic acid (11.9%), oleic acid (27.6%), and linoleic acid (30.1%), whereas small amounts of eicosapentaenoic acid (EPA, 3.7%) and docosahexaenoic acid (DHA, 8.4%) were also found. The predominant amino acids of all patties were arginine, glutamic acid, aspartic acid, leucine, threonine, and proline, and the contents of these amino acids in salmon patty were higher than in the two commercial patties. The Fe, Ca, K, P, and Mg contents of salmon patty were 2.4 mg/100g, 42.6 mg/100g, 207.5 mg/100g, 211.6 mg/100 g, and 29.9 mg/100 g, respectively. The sensory quality of salmon patty was higher than that of pork patty. These results indicate that salmon patty may have good quality characteristics, comparable to those of the two commercial patties.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.2
• /
• pp.149-157
• /
• 1988

This study was carried out to prepare the flavoring substance using sardine for instant soup, and to examine the taste compounds and storage stability of the product. In preparation of product, raw sardine are gutted, boiled for 10 minutes and smoked 3 times to $9{\sim}10%$ moisture content at $80^{\circ}C$ for 8 hours. The smoked-dried sardine meat were followed to be 50 mesh of particle size. The powdered-dried sardine were mixed 4.0% sugar, 20.0% table salt, 3.0% monosodium glutamate, 0.2% black pepper, 0.2% garlic powder and 0.2% onion powder, Finally the powdered instant soup product were vacuum packed in a laminated film(PET/A1 foil/CPP) bag, and then stored at room temperature for 120 days. The effect of smoking on enhancing flavor and on preventing lipid oxidation of product during storage were observed. From the chemical analysis and omission test, the principal taste compounds of product were IMP, 478.2mg/l00g; free amino acids such as glutamic acid, histidine, arginine, phenylalaine 3292.5mg/l00g; non-volatile organic acids such as lactic acid, ${\alpha}-ketoglutaric$ acid, 712.2mg/l00g; total creatinine 409.0mg/100g, and small amount of betaine, TMAO. Fatty acid composition of product were mainly consisted of polyenoic acids such as 20:5, 22:6, followed by saturated acids, monoenoic acid. The major fatty acid were 16:0, 16:1, 18:1, 20:5 and 22:6. From the results of sensory evaluation and chemical experiments during storage, the vacuum packed product were good condition for preserving the quality during storage for 120 days. We may conclude that the quality of present product was not inferior to that of seasoning powder of anchovy on the market, and it can be commercialized as a flavoring substance in preparing soup and broth.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.10
• /
• pp.1618-1625
• /
• 2004

Beans are acknowledged to be food resources, which have more abundant proteins and fats. The constituent parts of beans (i.e. aspartic aid, glycine, arginine) are effective against diabetes, and dietary fiber contained in the beans has an important property to maintain insulin sensitivity. Based on these, using streptozotocin (STZ)-induced diabetic rats, this study examined how the rat-eye soybean, which is principal products of the Imsil province, is effective to attenuate and/or prevent the development of diabetes mellitus. We divided rats into the non-diabetic and diabetic group, and diabetic group was further subdivided into six experimental groups [DC, diabetic control; DI, diabetes with insulin treatment (4∼6 IU/rat); DB, diabetes with black bean; DY, diabetes with yellow soybean; DS, diabetes with rat-eye soybean; DSS, diabetes with vinegar-fermented rat-eye soybean. All bean treatment (1.5 mg/l g body weight).]. Food efficiency ratio (FER), body weight and insulin sensitivity in diabetic rats were significantly reduced compared to those in normal control animals. These reductions were obviously attenuated by administration of a variety of beans used in this study (20∼30%), and the recovery effects were comparable to the results obtained by insulin treatment. Taken together, this study suggests that all beans used may have an essential property to improve and/or attenuate the development of diabetes mellitus in rats.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.6
• /
• pp.392-399
• /
• 2000

This study was carried out to investigate the physicochemical characteristics of corn silks. Pollination of corn silks was finished within three days after silking, and elongation of open pollinated corn silks was stopped, but unpollinated silks elongated until eight days after silking. Moisture contents of corn silks were about 92-94% at silking stage, but continuously decreased. these were about 70-75% at 30 days after silking. Chlorophyll b was higher than chlorophyll a in corn silks, and chlorophyll a/b ratios of four hybrids were high in this order : silage ＞ sweet ＞ super sweet ＞ waxy corn. Free sugars in corn silks were mainly fructose, glucose and maltose. Their composition rate was 55% of glucose, 42% of fructose and 4% of maltose. Water soluble solid (Brix %) contents of unpollinated corn silks were ranged from 13.7 to 16.8 Brix % and pollinated corn silks were from 12.6 to 13.7 Brix %. Phytic, oxalic, malic. shikimic, glutaric and acetic acid were detected on corn silks. Phytic, oxalic and glutaric acid were considered as a major organic acids in corn silks. Amino acids in corn silks were high in this order : waxy ＞ silage ＞ sweet ＞sweet corn. Serine, glycine and thereoine were contained more than 10%, and five amino acids such as aspartic, glutaric, arginine, alanine and proline were ranged about 5 to 8%. Methionine and cystine, amino acids containing sulfur were contained only small quantity as about 2.1% and 1.3%, respectively. Acetaldehyde, ethanol, acetone, DMS, isobutylaldehyde, cis-3-hexanol, 3-hexe-1-ol, acetate, trans-2-hexanol and pentanol were detected as the volatile components in corn silks, but acetaldehyde and DMS were major volitiles in silage corn silks, and acetaldehyde, ethanol and DMS were major volitiles in waxy corn silks. The length of corn silks was a positively correlated with organic acids (r=${0.556}^*$), and a negatively correlated with amino acids (r=${-0.514}^*$), respectively. Free sugars were positively correlated with all characteristics tested and significantly correlated with organic acid (r=TEX>${0.703}^{**}$), and flavonoids (r=TEX>${0.544}^*$). Chlorophyll was significantly correlated with flavonoid contents (r=TEX>${0.523}^*$). For this reason chlorophyll was evaluated as an indirect selection character for the high flavonoid containing varieties.