• Journal of Applied Biological Chemistry
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• v.56 no.1
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• pp.19-22
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• 2013

Plum (Prunus salicina L.) slices were dehydrated with red algae extract (RAE) at a concentration of 30% (w/w), and the dried samples were compared with maltodextrin (MD)-treated and hot-air dried samples in terms of physicochemical properties such as rehydration ratio, ascorbic acid, microstructure, and color. The rehydration ratios and colors of RAE-treated plum slices were better than those of MD-treated and hot-air dried samples. The ascorbic acid contents of RAE-treated samples were higher and their microstructures were finer than those of MD-treated or hot-air dried samples. These results suggest that plum slices can be dehydrated with RAE without loss of quality.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.520-528
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• 1996

The involvement of the cyclic AMP (cAMP) effector system in the release of endogenous dopamine and acetylcholine from the rat neostriatum was assessed. Forskolin, an activator of adenylate cyclase, was used to enhance cAMP production, and the consequence of this enhancement on the spontaneous and potassium stimulated release of dopamine and acetylcholine was evaluated. Neostriatal slices were prepared from Fischer 344 rats and after a preincubation period the release of each endogenous neurotransmitter was measured from the same slice preparation. To measure acetylcholine release the slice acetylcholinesterase (AChE) activity was inhibited with physostigmine, but the release from slices with intact AChE activity was also determined (choline, instead of acetylcholine was detected in the medium). Under both conditions forskolin induced a significant dose-dependent increase in the potassium-evoked release of dopamine. In the same tissue preparations the release of neither acetylcholine (AChE inhibited) nor choline (AChE intact) was affected by forskolin. The results indicate that the CAMP second messenger system might be involved in neuronal mechanisms that enhance neostriatal dopamine release, but stimulation of this second messenger by forskolin does not further enhance neostriatal acetylcholine release.

• Journal of Plant Biology
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• v.25 no.2
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• pp.65-72
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• 1982

The oxygen consumption of fresh and aged slices of potato tuber was 40.6 and 168.0 ,$0_2$ $\mu$l/g fr $wt{\cdot}h$, respectively. After initial burst of oxygen consumption within 2 minutes(i.e., 40% for fresh and 12% for aged slices) in the treatmentof $50{\mu}M$ alantolactone, gradual decrease of respiration rate was observed during 3 hours of incubation. In case of the aged slices the initial burst of oxygen consumption was not observed by salicylhydroxamic acid (SHAM) or KCN. The combined effect of SHAM and alantolactone showed increase of 12%, while SHAM and KCN combination showed 60% decrease. In addition, the lipophilicity of cell membrane of onion inner epidermis was increased by lantolactone treatment. The results suggest that the primary effect of alantolactone on the cellular respiration may be associated with an alteration of lipophilic phase of cell membrane and a consequent increase of electron flow throuh the cytochrome system.

• Journal of Acupuncture Research
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• v.18 no.3
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• pp.123-133
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• 2001

Objective : This study was undertaken to determine whether Cordyceps sinensis Sacc. (CSS) extract exerts the protective effect against oxidant-induced alterations in membrane transport function in renal tubules. Methods : Membrane transport fucntion was estimated by examining alterations in p-aminohippurate (PAH) uptake in rabbit renal cortical slices. For induction oxidative stress, slices were treated with an organic peroxide cumene hydroperoxide for 60 min at $37^{\circ}C$. Cumene hydroperoxide inhibited PAH uptake in a time dependent manner. Results : CSS at 0.5-5% concentrations prevented cumene hydroperoxide-induced inhibition of PAH uptake. CSS at 1% also attenuated LDH release and lipid peroxidation induced by cumene hydroperoxide. When slices were treated with 0.2 mM mercury chloride, PAH uptake was inhibited and lipid peroxidation was increased. These changes by mercury were significantly prevented by CSS. Conclusion : These results suggest that CSS prevents oxidant-induced alterations in membrane transport function in rabbit renal cortical slices. Such protective effect of CSS may be attributed to inhibition of peroxidation of membrane lipid.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.6
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• pp.301-305
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• 2004

This study examined the effects of N-methyl-D-aspartate (NMDA), ${\alpha}-amino$-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate on basal and electrically-evoked release of acetylcholine (ACh) from the rat hippocampal and striatal slices which were preincubated with $[^3H]choline$. Unexpectedly, the basal and evoked ACh release were not affected at all by the treatment with NMDA $(3{\sim}100{\mu}M)$, AMPA $(1{\sim}100{\mu}M)$ or kainate $(1{\sim}100{\mu}M)$ in hippocampal slices. However, in striatal slices, under the $Mg^{2+}-free$ medium, $30{\mu}M$ NMDA increased the basal ACh release with significant decrease of the electrically-evoked releases. The treatment with $1{\mu}M MK-801 not only reversed the $30{\mu}M$ NMDA-induced decrease of the evoked ACh release, but also attenuated the facilitatory effect of $30\;{\mu}M$ NMDA on the basal ACh release. The treatment with either $30\;{\mu}M$ AMPA or $100\;{\mu}M$ kainate increased the basal ACh release without any effects on the evoked release. The treatment with $10{\mu}M$ NBQX abolished the AMPA- or kainate-induced increase of the basal ACh release. Interestingly, NBQX significantly attenuated the evoked release when it was treated with AMPA, although it did not affect the evoked release alone without AMPA. These observations demonstrate that in hippocampal slices, ionotropic glutamate receptors do not modulate the ACh release in cholinergic terminals, whereas in striatal slices, activations of ionotropic glutamate receptors increase the basal ACh release though NMDA may decrease the electrically-evoked ACh release.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.61-67
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• 1991

In order to determine possible relationships between the renin-angiotensin system and nephron heterogeneity, we compared the response of renin release and the angiotensin-converting enzyme (ACE) activity from different areas of the rat kidney. We used the renal cortical slices from the capsular surface to the juxtamedullary junction. Slices from outer one-third of the cortex were designated as outer cortical slices (OC), middle one-third as midcortical slices (MC), and inner one-third as inner cortical slices (IC). The renal renin content markedly decreased from OC and MC to IC. The basal lenin release was higher in OC than in MC or IC. On the contrary the percent change of renin release in response to L-isoproterenol was significantly higher in MC than in OC or IC. By TMB-8, the renin release in MC by $231{\pm}21%$ was higher than OC by $171{\pm}19%$ or IC by $$162{\pm}19. Angiotensin II suppressed renin release in OC and MC by $68{\pm}2,\;71{\pm}4%$ respectively, but only $40{\pm}7%$ in IC. The ACE activity was higher in IC than in OC, MC, medulla and papilla. The present data indicate that renin content and basal lenin release gradulally decreased from outer (OC) to inner (IC) cortex. The renin release in response to beta-adrenergic agonist, L-isoproterenol and intracellular calcium antagonist, TMB-8 were higher in MC than in OC and IC, but angiotensin II suppressed renin release less in IC than in OC and MC. It is suggested that juxtaglomerular cells of outer, mid-and inner cortices show a difference in renin release response to the stimuli.

• Toxicological Research
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• v.13 no.4
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• pp.359-365
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• 1997

Many factors are known to be responsible for cerebral ischemic injury, such as excitatory neurotransmitters, increased intraneuronal calcium, or disturbance of cellular energy metabolism. Recently, oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of ischemia/reperfusion injury. Therefore, to investigate the role of oxygen free radical during ischemia/reperfusion, in the present study the effect of endogenous oxygen free radical scavenger, superoxide dismutase / catalase(SOD / catalase) on the release of [$^3$H]-5-hydroxytryptamine([$^3$H]-5-HT) during hypoxia/reoxygenation in rat hippocampal slices was measured. The hippocampus was obtained from the rat brain and sliced 400 gm thickness with manual chopper. After 30 min's preincubation in the normal buffer, the slices were incubated for 20 min in a buffer containing [$^3$H]-5-HT(0.1 $\mu$M, 74 $\mu$Ci) for uptake, and washed. To measure the release of [$^3$H]-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through a sequence of 14 tubes. Induction of hypoxia for 20 min (gassing it with 95% N$_2$/5% CO$_2$) was done in the 6th and 7th tube, and oxygen free radical scavenger, SOD / catalase was added 10 minutes prior to induction of hypoxia. The radioactivity in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. When slices were exposed to hypoxia for 20 min, [$^3$H]-5-HT release was markedly decreased and a rebound release of [$^3$H]-5-HT was observed on the post-hypoxic reoxygenation period. SOD / catalase did not changed the release of [$^3$H]-5-HT in control group, but inhibited the decrease of [$^3$H]-5-HT release in hypoxic period and rebound increase of [$^3$H]-5-HT in reoxygenation period. This result suggest that superoxide anion may play a role in the hypoxic-, and reoxygenation-induced change of [$^3$H]-5-HT release in rat hippocampal slices.

• Food Science and Preservation
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• v.31 no.2
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• pp.218-226
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• 2024

The oriental melon poses challenges in terms of long-term storage and distribution. Addressing these issues requires an extension of the storage life through appropriate processing. In this study, pretreated hot-air dried oriental melon slices (steamed and freeze-thawed) were prepared, and their physicochemical and organoleptic properties were examined. The control group (CON) consisted of hot-air dried oriental melon slices without pretreatment, while the steamed group (STG) and freeze-thawed group (FTG) consisted of hot-air dried oriental melon slices pretreated using steaming and freeze-thawing methods, respectively. The moisture contents detected in the CON, STG, and FTG groups ranged from 15.96% to 27.30%, with variations of 7.53 to 8.40 °Brix for the soluble solid contents. The CON group showed the highest Hunter color value for lightness (L^*) and the lowest value for redness (a^*). The texture profile analysis revealed the highest hardness and chewiness in the order of STG > CON > FTG. Considerable differences were observed in springiness and adhesiveness in the FTG group compared to the other groups. The organoleptic evaluation showed that the CON group had the highest sensory scores for overall preference. These findings indicate that the properties of hot-air dried oriental melon slices were influenced by physical pretreatments and that manufacturing these slices without pretreatment is the most effective method in terms of processing simplicity and cost efficiency.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.2
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• pp.239-247
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• 2010

This study was conducted to increase the keeping quality of the minimally processed pear slices during the cold storage. Korean pears, 'Shin-go (Niitaka)', 'Chu-hwang' and 'Won-hwang’ were immersed in 1% ascorbic acid, 0.1% calcium propionate, 1% citric acid, 0.2% N-acetyl cysteine and 0.5 M 4-hexylresorcinol solution for 3 three minutes and then stored at $1{\pm}0.5^{\circ}C$ for 10 days. We have also examined into the firmness and the color difference of pears slices as affected by the application of the anti-browning agents. The firmness of pears slices which that were immersed in 0.1% calcium propionate and 0.2% N-acetyl cysteine solution were not significant at did not differ significantly after 10 days after of cold storage. However, the ${\Delta}E^*$ values of 'Shin-go' slices which that were treated with 0.1% calcium propionate and 0.2% N-acetyl cysteine solution and stored for 10 days decreased by 3.18 and 3.83, when compared with that in of the control, which decreased by 6.36. The ${\Delta}E^*$ values of 'Chu-hwang' slices which that were treated with 0.2% N-acetyl cysteine and 0.1% calcium propionate solution had the slight difference by differed by only 2.09 and 2.14, when compared with that in of the control, which differed by 3.04. The ${\Delta}E^*$ values of 'Won-hwang' slices which that were treated with 1% citric acid and 0.5 M 4-hexylresorcinol were 4.49 and 5.83, respectively, while that in of the control decreased by 8.95. It was assumed that the anti-browning agent treatment had the different activities among varieties of the pear varieties slices, however, application of 0.2% N-acetyl cysteine and 0.1% calcium propionate application had greater the higher antibrowning activity.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.314-322
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• 2017

Purpose: This study was conducted to investigate the hot air drying characteristics of squash slices depending on the drying conditions (input air velocity, input air temperature, and sample thickness). Methods: The developed drying system was equipped with a controllable air blower and electric finned heater, drying chamber, and ventilation fan. Squash (summer squash called Korean zucchini) samples were cut into slices of two different thicknesses (5 and 10 mm). These were then dried at two different input air temperatures (60 and $70^{\circ}C$) and air velocities (5 and 7 m/s). Six well-known drying models were tested to describe the experimental drying data. A non-linear regression analysis was applied to determine model constants and statistical indices such as the coefficient of determination ($R^2$), reduced chi-square (${\chi}^2$), and root mean square error (RMSE). In addition, the effective moisture diffusivity ($D_{eff}$) was estimated based on the curve of ln(MR) versus drying time. Results: The results clearly showed that drying time decreased with an increase in input air temperature. Slice thickness also affected the drying time. Air velocity had a greater influence on drying time at $70^{\circ}C$ than at $60^{\circ}C$ for both thicknesses. All drying models accurately described the drying curve of squash slices regardless of slice thickness and drying conditions; the Modified Henderson and Pabis model had the best performance with the highest R2 and the lowest RMSE values. The effective moisture diffusivity ($D_{eff}$) changes, obtained from Fick's diffusion method, were between $1.67{\times}10^{-10}$ and $7.01{\times}10^{-10}m^2/s$. The moisture diffusivity was increased with an increase in input air temperature, velocity, and thickness. Conclusions: The drying time of squash slices varied depending on input temperature, velocity, and thickness of slices. The further study is necessary to figure out optimal drying condition for squash slices with retaining its original quality.