• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.6
• /
• pp.337-341
• /
• 2006

The present study was designed to investigate the protein expression of nitric oxide synthase (NOS) and guanylyl cyclase (GC) activity in ischemia/perfusion (I/R) renal injury in rats. Renal I/R injury was experimentally induced by clamping the both renal pedicle for 40 min in Sprague-Dawley male rats. The renal expression of NOS isoforms was determined by Western blot analysis, and the activity of guanylyl cyclase was determined by the amount of guanosine 3', 5'-cyclic monophosphate (cGMP) formed in response to sodium nitroprusside (SNP), NO donor. I/R injury resulted in renal failure associated with decreased urine osmolality. The expression of inducible NOS (iNOS) was increased in I/R injury rats compared with controls, while endothelial NOS (eNOS) and neuronal NOS (nNOS) expression was decreased. The urinary excretion of NO metabolites was decreased in I/R injury rats. The cGMP production provoked by SNP was decreased in the papilla, but not in glomerulus. These results indicate an altered regulation of NOS expression and guanylyl cyclase activity in I/R-induced nephropathy.

• Korean Journal of Food Science and Technology
• /
• v.27 no.2
• /
• pp.241-245
• /
• 1995

Focusing on quality problems of delayed chilling porcine muscle, the effects of delayed chilling and aging on the contents of ATP-related compounds and taste of pork were investigated. Twelve Landrace pigs were employed and bisected: left sides were delay-chilled(DC) at room temperature($20^{\circ}C$) for 3 hrs, whereas right sides were conventionally chilled(CC). ATP-related compounds tested were adenosine triphosphate(ATP) and its derivatives in pork muscle, inosine monophosphate(IMP), guanosine monophosphate(GMP) and L-glutamate in cooked broth. DC sides showed more rapid pH decline and degradation of nucleotides than did CC sides. The levels of ATP and adenosine monophosphate(AMP) were not changed significantly. However, adenosine diphosphate(ADP) and IMP showed the highest levels at the 1st and 5th day, respectively. Hypoxanthine(Hx) was gradually increased(p<0.05) during aging. During aging, the IMP contents cooked broth tended to decrease, while the GMP and L-glutamate contents increase. As a result of these, the taste score got better and finally the results of sensory evaluation became increased(p<0.05). However, compared to CC sides, DC sides did not seem to lower taste of pork.

• Journal of Ginseng Research
• /
• v.39 no.2
• /
• pp.169-177
• /
• 2015

Background: Ginsenoside Rd (GSRd), one of the most abundant ingredients of Panax ginseng, protects the heart via multiple mechanisms including the inhibition of $Ca^{2+}$ influx.We intended to explore the effects of GSRd on L-type $Ca^{2+}$ current ($I_{Ca,L}$) and define the mechanism of the suppression of $I_{Ca,L}$ by GSRd. Methods: Perforated-patch recording and whole-cell voltage clamp techniques were applied in isolated rat ventricular myocytes. Results: (1) GSRd reduced $I_{Ca,L}$ peak amplitude in a concentration-dependent manner [half-maximal inhibitory concentration $(IC_{50})=32.4{\pm}7.1{\mu}mol/L$] and up-shifted the current-voltage (I-V) curve. (2) GSRd ($30{\mu}mol/L$) significantly changed the steady-state activation curve of $I_{Ca,L}$ ($V_{0.5}:-19.12{\pm}0.68$ vs. $-6.26{\pm}0.38mV$; n = 5, p < 0.05) and slowed down the recovery of $I_{Ca,L}$ from inactivation [the time content (${\zeta}$) from 91 ms to 136 ms, n = 5, p < 0.01]. (3) A more significant inhibitive effect of GSRd ($100{\mu}mol/L$) was identified in perforated-patch recording when compared with whole-cell recording [$65.7{\pm}3.2%$ (n = 10) vs. $31.4{\pm}5.2%$ (n = 5), p < 0.01]. (4) Pertussis toxin ($G_i$ protein inhibitor) completely abolished the $I_{Ca,L}$ inhibition induced by GSRd. There was a significant difference in inhibition potency between the two cyclic adenosine monophosphate elevating agents (isoprenaline and forskolin) prestimulation [$55{\pm}7.8%$ (n = 5) vs. $17.2{\pm}3.5%$ (n = 5), p < 0.01]. (5) 1H-[1,2,4]Oxadiazolo[4,3-a]-quinoxalin-1-one (a guanylate cyclase inhibitor) and N-acetyl-$\small{L}$-cysteine (a nitric oxide scavenger) partly recovered the $I_{Ca,L}$ inhibition induced by GSRd. (6) Phorbol-12-myristate-13-acetate (a protein kinase C activator) and GF109203X (a protein kinase C inhibitor) did not contribute to the inhibition of GSRd. Conclusion: These findings suggest that GSRd could inhibit $I_{Ca,L}$ through pertussis toxin-sensitive G protein ($G_i$) and a nitric oxide-cyclic guanosine monophosphate-dependent mechanism.

• Journal of Pharmacopuncture
• /
• v.27 no.2
• /
• pp.82-90
• /
• 2024

Objectives: Nitric oxide is the most important mediator of penile erection after the onset of sexual excitement. It activates cyclic guanosine monophosphate (cGMP), increasing penile blood flow. Most pharmaceutical medications prevent enzyme phosphodiesterase type 5 (PDE-5) from breaking down cGMP, thus keeping its level high. However, due to the adverse effects of pharmacological therapies, herbal drugs that improve sexual function have gained attention recently. This study aimed to investigate the combined effects of ginseng, Tribulus terrestris, and L-arginine amino acid on the sexual performance of individuals with erectile dysfunction (ED) using the 5-item version of the International Index of Erectile Function (IIEF-5) questionnaire. Methods: Over three months, 98 men with erectile dysfunction were randomly assigned to receive either 500 mg of herbal supplements or placebo pills. Each herbal tablet contained 100 mg of protodioscin, 35 mg of ginsenosides, and 250 mg of L-arginine. Results: The results showed that the changes in the average scores of ILEF-5 within each group before and after the intervention indicated that all parameters related to the improvement of sexual function in patients with erectile dysfunction improved in the herbal treatment group (p < 0.001). The herbal group significantly improved IIEF-5 scores in nondiabetics (p < 0.05). However, there was no significant difference in the changes of IIEF-5 scores between the two intervention and control groups in diabetic patients. Conclusion: In conclusion, ginseng, Tribulus terrestris, and L-arginine have properties that increase energy and strengthen sexual function, making them suitable for patients with sexual disorders.

• Korean Journal of Food Science and Technology
• /
• v.22 no.2
• /
• pp.221-226
• /
• 1990

Fish flesh of Alaska pollack containing 5% of corn starch were fermented with 8 strains of mold and monitoring of their flavor characteristics, acceptability, nucleotides and their related compounds, amino acid compositions were conducted. All strains were grown vigorously on fish flesh media and formed their characteristic spores with unique flavor by strains. Amino type nitrogen $(NH_2-N)$ content of fermented fish flesh (FFF) were 25-26 times higher than that of raw flesh and 6-15 times higher in extractable nitrogen (Ex-N) content . The strains which produce more ADP (Adenosine 5'-diphosphate) in FFF also showed much higher level of IMP (Inosine 5'-monophosphate) and GMP (Guanosine 5'-monophosphate) content than that of raw flesh. Amino acid composition were differ by strain but lysine was generally highest and arginine, glutamic acid, leucine and alanine in order In review of sensory evaluation , total content of nucleotides, $NH_2-N$, Ex-N and amino acid compositions, suitable strains for fish flesh fermentation were Aspergillus oryzae KFCC 11371, Asp. oryzae KFCC 32343, Penicillium roqueforti KFCC 11269 and Asp. quercinus.

• Proceedings of the Ginseng society Conference
• /
• 1993.09a
• /
• pp.40-48
• /
• 1993

Intravenous administration of saponin extracted from the root of Panax ginseng lowered the blood pressure dose-dependently (10-200 mg/kg, B.W) in anesthetized rats. Therefore, experiments were designed to study the hypothesis that the lowering of blood pressure is associated with the release of endothelium-derived relaxing factor and the accumulation of guanosine 3, 5-cyclic monophosphate (cGMP). Rings of thoracic aorta with and without endothelium were suspended for the measurement of isometric tension in organ chamber and the tissue content of cGMP was measured by radioimmunoassay. All experiments were performed in the presence of $indomethacin(10^{-5}M).$ Ginseng saponin $(10^{-5}-3{\times}10^{-6}g/ml)$ relaxed contractions induced by phenylephrine $10^{-6}M)$ in the aorta with endothelium but not in that without endothelium. Treatment of aortic rings with $N^G$ monomethyl-L-arginine (L-NMMA, $10^{-4}M$ for 30 min), a competitive inhibitor of nitric oxide synthase, and methylene blue $(MB,\;3{\times}10^{-7}M$ for 30 min). an inhibitor of soluble guanylate cyclase, diminished the relaxation induced by Ginseng saponin. Ginseng saponin $10^{-4}g/ml$ for 2 min) increased the accumulation of cGMP in rings with endothelium. L-NMMA and MB inhibited the accumulation of cGMP induced by Ginseng saponin. These data suggest that vascular relaxations induced by Ginseng saponin are mediated by release of endothelium-derived relaxing factor and the accumulation of cGMP. The effect of Ginseng saponin on endothelial function in hypercholesterolemic rabbits was examined. In hypercholesterolemic rabbits fed with $2\%$ cholesterol for 8 weeks, relaxation of aortic rings to acetylcholine was impaired. The impaired relaxations of aortic rings in hypercholesterolemic rabbits were improved by dietary supplementation of Ginseng saponin, probably because of an improved release of endothelium - derived relaxing factor.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.5
• /
• pp.569-577
• /
• 2007

The purpose of the present study was to propose some amendments on nutrient standard regulations of infant formula in Korea. For this purpose, we compared and analyzed the nutrient regulations of Korea, CODEX, U.S.A, Japan, EU, Australia and New Zealand. Some developing aspects of Korea's nutrient standard regulations for infant formula need to be examined as follows: firstly, both milk-based formula and soy-based formula standards would be unified into an infant formula, and the user of infant formula would be categorized for babies less than 6 month old. Secondly, nitrogen conversion factor of milk protein in the infant formula would be 6.38, which is the same as that of CODEX Revised Standard. Protein quantities could be differentiated by protein sources, and essential amino acids in human milk would be standardized according to protein contents. Thirdly, $\alpha$-linolenic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) as essential fatty acids and trans fatty acid would be standardized in terms of the contents. Fourthly, it is recommended that the unit of vitamins and minerals would be changed from g/100 g to g/100 kcal, and individual vitamins and mineral would have their maximum values. Finally, 5 nucleotides (cytidine, uridine, adenosine, guanosine, inosine 5'-monophosphate) and fluoride would be required for the strengthening the immunity and the development of teeth, respectively. In conclusion, the scientific studies on amendment scheme of nutrient standard regulations of infant formula is very important to fortify nutritional completeness for Korean infants and young children.

• The Korean Journal of Physiology and Pharmacology
• /
• v.13 no.6
• /
• pp.503-510
• /
• 2009

To elucidate the mechanism of cyclic nucleotides, such as adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP), in the regulation of human gastric motility, we examined the effects of forskolin (FSK), isoproterenol (ISO) and sodium nitroprusside (SNP) on the spontaneous, high $K^+$ and acetylcholine (ACh)-induced contractions of corporal circular smooth muscle in human stomach. Gastric circular smooth muscle showed regular spontaneous contraction, and FSK, ISO and SNP inhibited its phasic contraction and basal tone in a concentration-dependent manner. High $K^+$ (50 mM) produced sustained tonic contraction, and ACh $(10\;{\mu}M)$ produced initial transient contraction followed by later sustained tonic contraction with superimposed phasic contractions. FSK, ISO and SNP inhibited high $K^+$-induced tonic contraction and also ACh-induced phasic and tonic contraction in a reversible manner. Nifedipine $(1\;{\mu}M)$, inhibitor of voltage-dependent L-type calcium current $(VDCC_L)$, almost abolished ACh-induced phasic contractions. These findings suggest that FSK, ISO and SNP, which are known cyclic nucleotide stimulators, inhibit smooth muscle contraction in human stomach partly via inhibition of $VDCC_L$.

• Korean Journal of Agricultural Science
• /
• v.42 no.4
• /
• pp.369-374
• /
• 2015

This study was conducted to compare the glucose, lactate, and nucleotide degradation products content of cooked beef steaks from Korean Hanwoo (quality grade: 1) and Australian cattle (Bos indicus, grain-fed for 100 d) by internal temperature. The loins (M. longissimus dorsi) and top rounds (M. semimembranosus) from two cattle breeds were cut into about 2 cm thickness and then cooked in a $180^{\circ}C$ electronic oven until internal temperature attained to 50, 70, or $90^{\circ}C$. Regardless of internal temperature, glucose content was higher (P<0.05) in cooked loin and top round steaks from Hanwoo compared to those from Australian cattle. Lactate content was shown to be lower (P<0.05) in cooked steaks from Hanwoo than in those from Australian cattle. Lower (P<0.05) hypoxanthine and higher (P<0.05) guanosine 5'-monophosphate, inosine 5'-monophosphate, inosine contents were observed in cooked steaks from Hanwoo. Furthermore, glucose content tended to be decreased by internal temperature but nucleotide degradation products content was not changed by internal temperature. Therefore, these findings suggest that cooked Hanwoo beef steaks had higher flavor precursors related to sweet and umami tastes than cooked Australian beef steaks

• The Korean Journal of Physiology and Pharmacology
• /
• v.15 no.5
• /
• pp.273-277
• /
• 2011

Nitric oxide (NO) and atrial natriuretic peptide (ANP) may induce vascular relaxation by increasing the production of cyclic guanosine monophosphate (cGMP), an important mediator of vascular tone during sepsis. This study aimed to determine whether regulation of NO and the ANP system is altered in lipopolysaccharide (LPS)-induced kidney injury. LPS (10 $mg{\cdot}kg^{-1}$) was injected in the tail veins of male Sprague-Dawley rats; 12 hours later, the kidneys were removed. Protein expression of NO synthase (NOS) and neutral endopeptidase (NEP) was determined by semiquantitative immuno-blotting. As an index of synthesis of NO, its stable metabolites (nitrite/nitrate, NOx) were measured using colorimetric assays. mRNA expression of the ANP system was determined by real-time polymerase chain reaction. To determine the activity of guanylyl cyclase (GC), the amount of cGMP generated in response to sodium nitroprusside (SNP) and ANP was calculated. Creatinine clearance decreased and fractional excretion of sodium increased in LPS-treated rats compared with the controls. Inducible NOS protein expression increased in LPS-treated rats, while that of endothelial NOS, neuronal NOS, and NEP remained unchanged. Additionally, urinary and plasma NOx levels increased in LPS-treated rats. SNP-stimulated GC activity remained unchanged in the glomerulus and papilla in the LPS-treated rats. mRNA expression of natriuretic peptide receptor (NPR)-C decreased in LPS-treated rats, while that of ANP and NPR-A did not change. ANP-stimulated GC activity reduced in the glomerulus and papilla. In conclusion, enhancement of the NO/cGMP pathway and decrease in ANP clearance were found play a role in the pathogenesis of LPS-induced kidney injury.