• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.835-845
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• 2018

We studied the role of ethylene control in regulating energy metabolism, antioxidant enzyme activity, and vase life of cut rose Rosa hybrida 'Carola'. Rose flowers at stage II were sprayed with one of the following solutions: water (control), $10{\mu}L\;L^{-1}$ 1-methylcyclopropene (1-MCP), or $0.5g\;L^{-1}$ 2-chloroethanephosphonic acid (ethephon). After harvest, ethylene production rate, respiration intensity, energy charge (EC), activities of energy metabolism-related and antioxidant enzymes, and malondialdehyde (MDA) content were measured. Results showed that 1-MCP enhanced the activities of superoxide dismutase, $H^+$-adenosine triphosphatase, $Ca^{2+}$-adenosine triphosphatase, succinic dehydrogenase, and cytochrome c oxidase, increased adenosine triphosphate (ATP) content, maintained high EC levels, inhibited respiration intensity, reduced peroxidase (POD) and polyphenol oxidase (PPO) activity and MDA accumulation, and prolonged vase life. Ethephon promoted ethylene production and respiration intensity, increased POD and PPO activity, reduced ATP content and EC levels, and accelerated senescence. Our results support a novel role for ethylene control in regulating senescence of 'Carola'.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.1
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• pp.59-68
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• 1999

Chemically induced hypoxia has been shown to induce a depletion of ATP. Since intracellular free $Mg^{2+}\;([Mg^{2+}]_i)$ appears to be tightly regulated following cellular energy depletion, we hypothesized that the increase in $[Mg^{2+}]_i$ would result in $Mg^{2+}$ extrusion following hormonal stimulation. To determine the relation between $Mg^{2+}$ efflux and cellular energy state in a hypoxic rat heart and isolated myocytes, $[Mg^{2+}]_i,$ ATP and $Mg^{2+}$ content were measured by using mag-fura-2, luciferin-luciferase and atomic absorbance spectrophotometry. $Mg^{2+}$ effluxes were stimulated by norepinephrine (NE) or cAMP analogues, respectively. $Mg^{2+}$ effluxes induced by NE or cAMP were more stimulated in the presence of metabolic inhibitors (MI). Chemical hypoxia with NaCN (2 mM) caused a rapid decrease of cellular ATP within 1 min. Measurement of $[Mg^{2+}]_i$ confirmed that ATP depletion was accompanied by an increase in $[Mg^{2+}]_i.$ No change in $Mg^{2+}$ efflux was observed when cells were incubated with MI. In the presence of MI, the cAMP-induced $Mg^{2+}$ effluxes were inhibited by quinidine, imipramine, and removal of extracellular $Na^+.$ In addition, after several min of perfusion with $Na^+-free$ buffer, a large increase in $Mg^{2+}$ efflux occurred when $Na^+-free$ buffer was switched to 120 mM $Na^+$ containing buffer. A similar $Mg^{2+}$ efflux was observed in myocytes. These effluxes were inhibited by quinidine and imipramine. These results indicate that the activation of $Mg^{2+}$ effluxes by hormonal stimulation is directly dependent on intracellular $Mg^{2+}$ contents and that these $Mg^{2+}$ effluxes appear to occur through the $Na^+-dependent\;Na^+/Mg^{2+}$ exchange system during chemical hypoxia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1210-1214
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• 2009

Early postmortem ATP level is known as a good predictor of pork quality. Pork carcasses were divided into two; one was electrically stimulated (ES) to simulate poor quality pork and the other was left untreated and served as a control normal pork. Fractions of longissimus were excised from carcasses regularly for 2 hours after death and deep-frozen ($-80^{\circ}C$) until analyses. The ATP level of normal untreated control pork decreased from 5.00 to 2.04 ${\mu}mole$/g within 2 hours postmortem. The decrement of ATP was approximately 60% of its initial content. In the meantime, ES poor quality pork had a more drastic rate of ATP decrease. Electrical stimulation itself decreased ATP level from 4.70 to 3.50 ${\mu}mole$/g, by approximately 25%. ATP level of ES pork dropped to 1.71 ${\mu}mole$/g within 1 hour postmortem and was further plunged to 0.26 ${\mu}mole$/g and almost exhausted during the next hour. The level of IMP increased from 0.49 to 3.17 ${\mu}mole$/g and it became the dominant nucleotide within 2 hours postmortem. Electrical stimulation prompted the increase of IMP from 0.69 to 3.19 ${\mu}mole$/g and its level went up to 6.64 ${\mu}mole$/g within 2 hours postmortem. The level of ADP also decreased from 1.45 to 0.67 ${\mu}mole$/g for 2 hours after death and ES also accelerated ADP breakdown. The AMP levels were lower than those of other nucleotides and increased from 0.16 to 0.31 ${\mu}mole$/g within 2 hours postmortem. The increase of AMP was accelerated between 60 and 90 minutes after electrical stimulation. Early postmortem electrical stimulation prompted a drastic rate of changes in contents of 4 nucleotides during 2 hours postmortem. In the meantime, the ATP levels for ES poor quality pork were much lower than those of normal pork.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.403-408
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• 1993

To clarify the effects of killing methods on biochemical changes of plaice, Paralichthys olivaceus muscle at early period after death, cultured plaices were killed by the following four different methods; 1. spiking at the brain instantly. 2. letting them to die in the air. 3. dipping in sea water including anesthetic. 4. electrifying in sea water. Immediately after death, the changes in ATP and its related compounds, ATP breakdown, and IMP or lactate accumulation rates of muscle during storage at $5^{\circ}C$ were studied. ATP in samples killed by letting and electrifying were decomposed more rapidly than spiking and dipping samples. The rate constant of ATP breakdown were $0.429h^{-1}$ for samples killed by electrifying, $0.224h^{-1}$ for letting samples, $0.195h^{-1}$ for spiking samples, and $0.167h^{-1}$ for dipping samples. The maximum speed and content of IMP or lactate accumulation were showed in samples killed by electrifying among the all killing methods. The rate constant of lactate accumulation were $2.256h^{-1}$ for samples killed by electrifying, $1.123h^{-1}$ for letting samples, $0.534h^{-1}$ for spiking samples, and $0.526h^{-1}$ for dipping samples. From the results above, it was revealed that electrifying in sea water could accelerate ATP breakdown and accumulation of IMP or lactate among the all killing methods. The other hand, dipping in sea water including anesthetic delayed those changes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.189-196
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• 1992

To know the extension effect of storage temperature on the pre-rigor period of plaice, Paratichthys olivaceus muscle, the relationship between early changes after death and temperature dependency was studied. Killed plaices instantly with spiking at the brain were stored at $-3^{\circ}C,\;0^{\circ}C,\;5^{\circ}C\;and\;10^{\circ}$ used in studying the changes in rigor Index, ATP and its related compounds, lactate contents and K-value. The most shortest onset time of rigor-mortis and full rigor was revealed in the sample stored at $-3^{\circ}C$ among the all samples, where rigor-mortis began at 4hrs after spiking and maximum tension was attained after 28hrs. However, in case of fresh plaice muscle stored at $10^{\circ}C$, the onset of rigor-mortis and full rigor were retarded to 14hrs and 52hrs after spiking. ATP in sample stored at $5^{\circ}C\;and\;10^{\circ}C$ were decomposed slowly than sample at $0^{\circ}C\;-3^{\circ}C $ and within 35hrs storage. The fastest rate and the maximum content of lactate accumulation were showed in sample stored at $-3^{\circ}$ among the all samples. The correlation coefficient(r) between the rate of rigor mortis and ATP breakdown, rigor mortis and lactate accumulation, and ATP breakdown and lactate accumulation were -0.981946, 0.965044, and -0.964728, respectively. Freshness of $-3^{\circ}C$ stored samples was maintained for the longest time compared with other stored samples. The times reached around $20\%$ of K-value were 240hrs for samples stored at $-3^{\circ}C,\;96hrs\;for\;0^{\circ}C\;samples,\;71hrs\;for\;5^{\circ}C\;samples,\;and\;22hrs\;for\;10^{\circ}C$ samples. Samples stored at $-3^{\circ}C,\;and\;0^{\circ}C$ were showed higher temperature dependency on rate of rigor-mortis, ATP breakdown, and lactate accumulation than $5^{\circ}C\;and\;10^{\circ}C$ stored samples, but those samples have a lower temperature dependency on K-value.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.9-15
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• 2000

To investigate changes of components in salt-fermented anchovy, Engraulis japonims sauce during fermentation, various chemical properties were examined at $1.5{\~}3$ months interval during 18 months fermentation. Moisture content and pH were decreased slightly, but the contents of VBN and crude protein, total and amino nitrogen, hydrolytic degree and absorbance at 453 nm were increased gradually during fermentation. On the other hand, ash content and salinity showed almost no change. Hk and uric acid were the most abundant in ATP related compounds, ranging from $80.1{\%}\;to\;92.7{\%}$ in salt-fermented anchovy sauce during the fermentation, After 18 months of fermentation the sauce was rich in free amino acids, such as glutamic acid, leucine, alanine, lysine, isoleucine, valine in that order.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.463-470
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• 1998

To improve muscle quality and prolong freshness of sashimi, the effects of freezing-thawing condition on physicochemical and rheological properties of plaice muscle were investigated. Muscle tested were frozen with quick freezing (liquid nitrogen gas) or slow freezing ($-15^{\circ}C$ air). Transition time of zone of ice crystal formation was within 10 minute for quick freezing and 110 minute for slow freezing. Time required for thawing to $0^{\circ}C$ in muscle temperature by various thawing methods was shortest with $25^{\circ}C$ tap water, followed by $15^{\circ}C$ tap water, $10^{\circ}C$ tap water, $25^{\circ}C$ air, $5^{\circ}C$ tap water and $0^{\circ}C$ cold water. Breaking strength of muscle was higher in quickly frozen sample than in slowly frozen sample. According to sashimi term, changes in breaking strength of muscle did not show any difference in quickly frozen sample, while showed significant difference in slowly frozen sample. The remaining content of ATP was not effected by freezing speed, and ATP content was apt to higher in quickly thawed sample than in slowly thawed sample. IMP was the majority of ATP and it's related compounds of sample after freezing and thawing. Collagen matrix was weakened markedly in slowly frozen sample than in quickly frozen sample.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.59-64
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• 1992

Salted and then washed flounder muscles with salting levels of 10%, 15% and 20% were mixed with boiled foxtail millet and spices(radish, garlic, ginger and red pepper) and fermented at $15^{\circ}C$ for 7 days. The changes of taste constituents of fermented flounder Sikhae, such as sugars, free amino acids and 5'-nucleotides, were investigated. The content of fructose decreased significantly during Sikhae fermentation, but the content of mannitol that was not detected from raw material was estimated to be $6.26%{\sim}8.97%$ in Sikhae. The content of total free amino nitrogen in the 15% salted Sikhae was 290.6 mg% and the highest value with 53.4% of its extract nitrogen. It is believed that leucine, alanine, arginine, glutamine, isoleucine, valine, glutamic acid and lysine may play an important role as the taste constituents in Sikhae. The detected 5'-nucleotides were CMP, UMP, CTP, AMP, ADP and ATP and among them the nucleotide showing the hightest level irrespective of treatment was UMP estimated to be $761.0\;{\mu}g{\sim}849.0\;{\mu}g/g$. ATP and ADP were significantly decreased in Sikhae, but CMP and CTP were significantly increased in the 15% salted Sikhae compared with those of raw material.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.3
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• pp.189-195
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• 2021

Fluoxetine (FLX), a selective serotonin reuptake inhibitor antidepressant, exhibits various other mechanisms of action in numerous cell types and has been shown to induce cell death in cancer cells, paving the way for its potential use in cancer therapy. The aim of this study was to determine the off-target effects of the anti-depressant drug FLX, on the human ovarian granulosa tumor COV434 cells stimulated by forskolin (FSK), by measuring the real-time kinetics of intracellular cyclic AMP (cAMP), ATP level, cytoplasmic calcium ([Ca2+]cyt) and survival of COV434 cells. We show that incubating COV434 cells with FLX (between 0.6 and 10 μM) induces a decrease in intracellular cAMP response to FSK, a drop in ATP content and stimulates cytoplasmic Ca2+ accumulation in COV434 cells. Only the highest concentrations of FLX (5-10 μM) diminished cell viability. The present report is the first to identify an action mechanism of FLX in human tumor ovarian cells COV434 cells and thus opening the way to potential use of fluoxetine as a complementary tool, in granulosa tumor treatments.

• Korean Journal of Microbiology
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• v.24 no.2
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• pp.147-153
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• 1986

Viable potential of Mycobacterium smegmatis, a slow grower in vitro cultivation and of M. leprae, an obligate intracellular parasitic bacterium, which can not be cultured yet in vitro was assessed by fluorospectrophotometry. Bacterial cells in different numbers and under various physiological status were incubater with fluorescein diacetate(FDA). After an incubation of the bacterial preparations with FDA at specified conditions, amount of fluorescein inside bacteria was measured by a fluorospectrophotometer at 470nm and 510nm of excitation and emission wavelengths, respectively. Fluorounit given by such bacteria showed a correlation with assessment of viability of the same preparations made by other methods, such as optical density and colony forming units of M. smegmatis and intracellular ATP content of M. leprae. The possible use of fluorospectrophotometry in assessing viability or physiological potential of bacteria, particularly intracellular parasites and fastidious organisms to culture in vitro is discussed in relation to other methods.