• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.513-521
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• 2009

The primary goal of this research was to develop an optimized analytical procedure for soil analysis based on ion-selective microelectrodes for agricultural purposes, which can perform on-site measurement of various ions in soil easily and rapidly. For the simple and rapid on-site diagnosis, an analysis of soil chemicals was performed employing a multicomponent-in-situ-extractant and an evaluation of ionselective microelectrodes were conducted through the regressive correlation method with a standard analytical approach widely employed in this area. Examination of sensor responses between various soil nutrient extractants revealed that 0.01M HCl and 1M LiCl provided the most ideal Nernstian response. However, 1M LiCl deteriorated the selective response for analytes due to high concentration (1M) of lithium cation. Thus, employing either 0.1M HCl as an extractant followed by 10 times dilution, or 0.01M HCl as an extractant without further dilution was chosen as the optimal extractant composition. A study of regressive correlation between results from ion-selective microelectrodes and those from the standard analytical procedure showed that analyses of $K^+$, $Na^+$, $Ca^{2+}$, and $NO_3{^-}$ showed the excellent consistency between two methods. However, the response for $NH_4{^+}$ suffered the severe interference from $K^+$. In addition, the selectivity for $Mg^{2+}$ over $Ca^{2+}$ was not sufficient enough since available ionophores developed so far do not provide such a high selectivity for $Mg^{2+}$. Therefore, as an agricultural on-site diagnostic instrument, the device in development requires further research on $NH_4{^+}$ analysis in the soil sample, development of $Mg^{2+}$-selective ionophore, and more detailed study focused on potassium, one of the most important plant nutrients.

• Reproductive and Developmental Biology
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• v.29 no.3
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• pp.175-180
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• 2005

This study was conducted to examine the effects of demecolcine-assisted enucleation and recipient cell cycle stage on the development of bovine somatic cell nuclear transfer (NT) embryos. In vitro cultured oocytes for $16\~20$ h were classified by first polar body (1st PB) extrusion and cell cycle stage (MI and MII) and treated $0.4\;{\mu}L/mL$ demecolcine for 40 min before enucleation. Enucleated oocytes were fused electrically with bovine ear skin cells, activated by Ca-ionophore+DMAP, and cultured in vitro. Most of eggs ($86.2\%$) treated with demecolcine protruded a chromosome mass and enucleated efficiently ($98.8\%$, (P<0.05). Demecolcine did not have a deteriorative effect on the development of NT embryos. Developmental rate of NT embryos reconstituted with oocytes extruded 1st PB significantly higher than that of NT embryos produced by oocytes without 1st PB ($18.2\%\;vs.\;4.6\%\cdot$, P<0.05). Cleavage and blastocyst formation rate of embryos reconstituted with MI oocytes ($69.4\%\;and\;5.9\%$, respectively) were significantly lower than those of embryos reconstituted with MII oocytes ($96.7\%\;and\;23.9\%$, respectively, P<0.05). From the present result, it is suggested that domecolcine is useful for the enucleation of recipient oocytes in bovine NT procedures, and MII oocytes rather than MI oocytes are more appropriate for recipient cytoplasm. Although, the potential to develop into blastocysts of NT embryos produced by 1st PB-nonextruded and MI oocytes was very low, these oorytes could be used for NT.

• The Korean Journal of Pharmacology
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• v.28 no.1
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• pp.81-89
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• 1992

Enuresis is a common voiding disorder among children. There are several therapeutic regimens for the disorder available today; behavioral therapies, psychotherapy, bladder training, sleep interruption, hypnosis and drug therapy. Recently, the efficacy of drug therapy has been acknowledged, particularly of antidepressants. Among the tricyclic antidepressants, imipramine is most frequently employed for the treatment of enuresis. Present study was undertaken to investigate the mechanism of imipramine on the contractility of urinary bladder in relation to the calcium modulation using isolated strips of rat detrusor urinae. 1. The electric fileld stimulation-induced contraction was abolished by imipramine, but partially inhibited by atropine. 2. Imipramine reduced the basal tone and diminished the phasic activity of detrusor muscle concentration-dependently, which was similar to that of diltiazem, a calcium channel blocker. 3. Imipramine suppressed the maximal responses and shifted the concentration-response curves of bethanechol and ATP to right. 4. Imipramine inhibited the calcium-induced recovery of tension in calcium-free physiologic salt solution (PSS) with a mode of action similar to that of diltizaem. 5. A23187, a calcium ionophore recovered the basal tone which had been reduced by imipramine in normal PSS. 6. In calcium-free PSS, A23187 could recover the abolished basal tone with the pretreatment of imipramine, but it exerted a partial recovery with the pretreatment of TMB-8, an inhibitor of intracellular calcium release. Based on these results, it is suggested that the inhibitory action of imipramine on the detrusor muscle exerted in part by blockade of the muscarinic and purinergic receptors, and interference with the influx of extracellular calcium, but not with the release of intracellular stored calcium, is involved in its mechanism of action.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.202-208
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• 1997

In order to investigate the mechanisms of epithelial ion transports, microsomes of soybean roots were prepared and the activity of microsomal ATPases was measured by an enzyme-coupled assay. The effects of various ions were evaluated on the total activity of microsomal ATPases and the average activity was 190 nmol/min/mg protein in the control solution containing $10\;mM\;Na^+\;and\;120\;mM\;K^+$. The activities were increased to 150% and decreased to 63% of the control activity in the solution containing $130\;mM\;K^+$ without $Na^+$ and in the solution containing $130\;mM{\;}Na^+$ without $K^+$, respectively. In general, the activity of microsomal ATPase was increased by$K^+$ in a concentration-dependent manner The activity was also increased at lower pH and relatively higher activities were observed in the pH range of $6{\sim}7$. However, the activity was decreased at weak alkaline $pH\;and{\sim}80%$ of the activity was inhibited at pH 9. Since intracellular $Ca^{2+}$ has been known to control the activity of various enzymes, we have investigated the effects of intra-and extrarnicrosomal $Ca^{2+}$ on the activity of microsomal ATPases. The maximal activity was obtained at the extrarnicrosomal $Ca^{2+}$ concentrations below 1 nM. The activity was gradually decreased by increasing $‘Ca^{2+}’$ concentration and 50% inhibition was observed at ${\sim}500{\;}{\mu}M{\;}Ca^{2+}$. The increase in luminal $Ca^{2+}$ concentration also inhibited the activity of microsomal ATPase. When the influx of external $Ca^{2+}$ was induced by $Ca^{2+}$ ionophore A23187 treatment, the activity was decreased by 30%; however, it was recovered by EGTA-induced chelation of $Ca^{2+}$. These results suggest that the presence of $Ca^{2+}$ regulation sites on both cytoplasmi and luminal sides of microsomal ATPases.

• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.304-309
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• 1992

Background: The alveolar macrophage may metabolize arachidonic acid through cyclooxygenase- and lipoxygenase- catalyzed pathways to produce a variety of metabolites of arachidonic acid. The production of these metabolites of arachidonic acid may enhance the defensive ability of the challenged lung. However, continued stimulation with the consequent production of proinflammtory metabolites of arachidonic acid, may ultimately enhance the disease process by contributing to chronic bronchoconstriction, fibrosis, and the persistent release of toxic oxygen species. Silicosis is an example of a disease process resulting from chronic exposure of the lung to foreign particles. This study was carried out to evaluate the changes of arachidonic acid metabolites from macrophages in experimental silicosis. Methods: We measured $PGE_2$, and $LTB_4$ in cultured macrophages taken from rats by radioimmunoassay at 24 and 48 hours after stimulation by silica dust, natural carbon dust, lipopolysaccharide, calcium ionophore (A23187) and medium (RPMI) as a control. For the experimental silicosis, 50 mg silica in 0.5 ml saline was administered intratracheally into the rat and grown to 20 weeks and measured $PGE_2$, and $LTB_4$ in the cultured macrophages lavaged from that rat. The used stimulants were the same as above. Results: 1) The amount of $PGE_2$ in the cultred macrophages from normal rat was significantly decreased in the group which was stimulated with silica dust for 48 hours compare with control non-stimulated group. 2) In the experimental silicosis group, $PGE_2$, release in cultured macrophages after 48 hours incubation with silica and natural carbon dust tended to be lower than those of non-stimulated group. 3) There were marked changes of $LTB_4$ in the groups of normal rats which were incubated with silica for 24, 48 hours and natural carbon for 48 hours compared with non-stimulated group. 4) In the experimental silicosis group, the release of $LTB_4$ was significantly increased macrophages cultured with silica and natural carbon dust after 24 and 48 hours incubation compared with non-stimulated group. Conclusion: The results of these studies suggest that the in vitro exposure of rat alveolar macrophge to silica and coal dust results in an alteration in alveolar macrophage metabolism of arachidonic acid that may promote an inflammatory reaction in lung tissue.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.3
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• pp.203-212
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• 2008

Objective: During cryopreservation process, cold shock and cryo-injury affect the fertilizing capacity of the sperm by damaging cell membranes with loss of functional integrity. A longstanding concept for preventing the cryo-damage is to stabilize the plasma membrane by incorporating cholesterol. This study was to determine the effects of cholesterol in freezing media on the motility and functional integrity of human sperm after cryopreservation. Methods: Control group (non-cholesterol treated) and different concentrations of cholesterol-treated sperm (14 healthy males) were frozen and thawed. After freezing and thawing of sperm, the quality of sperm was evaluated by sperm analysis, acrosome reaction test and sperm chromatin structure assay. Results: When human sperm were incubated in sperm freezing medium (SFM) containing $0.5{\mu}g$ cholesterol and then freezing/thawing, the motility of sperm have significantly improved compared to those untreated cholesterol ($33.46{\pm}1.48%$ vs. $30.10{\pm}1.07%$, p<0.05). The rate of calcium ionophore-induced acrosome reactions in post-thawed sperm was significantly higher than that ($53.60{\pm}1.60%$ vs. $47.40{\pm}1.86%$, p<0.05) in SFM containing cholesterol. Sperm chromatin structure assay revealed that DNA damage to the sperm in the cholesterol-treated group was lower than that of non-treated group. Conclusion: These results suggest that increased cholesterol content of sperm plasma membrane by supplementation of cholesterol in SFM improves sperm motility, capacitation status, and DNA integrity. Therefore, addition of cholesterol into SFM could be a useful for protecting human sperm from cold shock and cryo-injury during cryopreservation.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.89-96
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• 1999

Some of the information concerning sexual function in the male diabetes has been focused upon the problems of endocrine or semen parameters. However, the characteristics of acrosome reaction and spermatozoa concentration at the epididymis and vas deferens have scarcely been studied, and the causes of the infertility has not been critically identified. So, we designed to inspect the spermatozoa concentration and the characteristics of acrosome reaction at epididymis and vas deferens of diabetic Wistar rat induced by streptozotocin (STZ, 70 mg/kg, ip). Experimental animal was sacrificed at 3 days and 14 days after the STZ injection. In the diabetes-induced rat, the levels of insulin and glucose had a pattern of inverse proportion. The spermatozoa concentrations in caput and corpus epididymis were significantly decreased in all diabetic condition. In cauda epididymis, however, there was significant decrease in sperm concentration at 14 days onward. In diabetic rat, the spontaneous reaction rate of spermatozoa of cauda and vas deferens were significantly higher than the control group. The ARIC (acrosome reaction to ionophore challenge) value of caudal sperm was 28.7 at control, 22.1 at 3 days, and 8.3 at 14 days. In the present study the spermatozoa concentration was decreased and the spontaneous reaction rate was increased by diabetes. In ARIC-test, it is revealed that the fertility of spermatozoa of 14 days group was lower than control or 3 days group. Diabetes mellitus may be provoke the decreased fertilization rate and subsequent infertility and subsequent infertility.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.189-194
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• 1996

The effects of scorpion (Leiurus quinquestriatus hebraeus, Lqh) venom were evaluated on the activities of microsomal $Ca^{2+}-ATPase$ and $Ca^{2+}$ release channel prepared from the epithelial cells of pig airway. Whole venom of Lqh $(120\;{\mu}g/ml)$ increased the activity of microsomal $Ca^{2+}-ATPase$ about 32% in the tight-sealed microsomes and about 28% in the Triton X-100-treated or $Ca^{2+}$ ionophore A23187-treated leaky microsomes. Thapsigargin, a specific antagonist of $Ca^{2+}-ATPase$, inhibited 42% of total ATPase activity and also completely blocked the effects of Lqh venom, suggesting that Lqh venom directly activiates the microsomal $Ca^{2+}-ATPase$. In order to determine if Lqh venom increases the microsomal uptake of $^{45}Ca^{2+}$, Lqh venom was added in the uptake medium. The Lqh venom increased microsomal $^{45}Ca^{2+}$ uptake up to ${\sim}20%$ and the increase was only observed when heparin, an antagonist of $InsP_3$ receptor channel, was added in the uptake medium. Lqh venom in the absence of heparin unexpectedly decreased the rate and the amount of $^{45}Ca^{2+}$ uptake. These results were explained by simultaneous increases in $^{45}Ca^{2+}$ release as well as $^{45}Ca^{2+}$ uptake by Lqh venom. Lqh venom itself increased the release of $^{45}Ca^{2+}$ as much as $^{45}Ca^{2+}$ release by $4\;{\mu}m\;InsP_3$, implying that Lqh venom also activates $InsP_3$ receptor, microsomal $Ca^{2+}$ release channel. Based on these results, we suggest that the Lqh venom consists of at least two components; one activates the $InsP_3$ receptor and the other avates the $Ca^{2+}-ATPase$. Currently we a investigating the chemical and electrophysiological properties of the active components of Lqh venom.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.57-67
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• 2019

Particulate matters with a diameter of < $10{\mu}m$ (PM10) exert oxidative stress and inflammatory events in various organs. The purpose of this study was to examine the molecular mechanism of reactive oxygen species (ROS) production induced by PM10 in the human epidermal keratinocytes (HEKs). When cultured HEKs were exposed to PM10, ROS production was induced and it was inhibited by apocynin, an antioxidant. The mRNA expression of NADPH oxidase (NOX) family was analyzed in order to examine their role in PM10-induced ROS production. PM10 increased the mRNA expression of NOX1, NOX2, dual oxidase (DUOX) 1 and DUOX2. HEKs expressed DUOX1 and DUOX2 at higher levels compared to other NOXs. The mRNA expression of dual oxidase maturation factors, DUOXA1 and DUOXA2, was also increased by PM10. We examined whether these calcium-dependent enzymes, DUOX1 and DUOX2, mediate the PM10-induced ROS production. A selective intracellular calcium chelator, BAPTA-AM, attenuated ROS production induced by PM10 or calcium ionophore A23187. The small intereference RNA (siRNA)-mediated down-regulation of DUOX2, but not DUOX1, attenuated the ROS production induced by PM10. PM10 increased the expression of inflammatory cytokines such as interleukin $(IL)-1{\beta}$, IL-6, IL-8 and interferon $(IFN)-{\gamma}$. SiRNA-mediated down-regulation of DUOX2 suppressed the PM10-induced expression of $IFN-{\gamma}$ but not other cytokines. This study suggests that DUOX2 plays a crucial role in ROS production and inflammatory response in PM10-exposed keratinocytes.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.243-254
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• 1994

Inflammatory diseases, allergic and asthmatic disorders are caused by the mediator release from the activation of the phospholipase C (PLC), phospholipase D (PLD), methyltransferase or adenylate cyclase etc. during IgG or IgE cross-linking of high affinity receptors on mast cells or basophil surface. One important enzyme activated after IgG or IgE receptor cross-linking is PLD, the enzyme which converts phosphatidylcholine (PC) to phosphatidic acid (PA). Under the hypothesis that these may be some differences in mediator release according to the difference in PLD activity, we attempted to confirm the ginseng saponin effects on the PLD activity. We examined the PLD activity during the passively sensitized mast cell activation in the presence of single component of ginsenosides $(Rc,\;Rg_1,\;Rg_2,\;Rg_3)$. We also measured the amount of mediators (histamine and leukotrienes) released by stimulating with ovalbumin (OA) or calcium ionophore (CaI), Guinea Pig lung mast cells were purified using enzyme digestion, count current elutriation, and discontinuous Percoll density gradient. In purified mast cells prelabeled with $[^3H]$ arachidonic acid or $[^3H]$ palmitic acid, PLD activity was assessed more directly by the production of labeled PEt by PLD-mediated transphosphatidylation in the presence of ethanol. Histanine release was determined by Spectrophotofluorometry, and leukotrienes by radioimmunoassay. The PLD activity during the passively sensitized mast cell activation is increased up to $3{\sim}5times$. The PLD activity during the passively sensitized mast cell activation in the presence of all ginsenosides is decreased up to $4{\sim}11$ times. $Rg_l\;and\;Rg_2$ ginsenoside pretreatment decreased histamine and leukotrienes by 50% in the OA-induced or by 40% in the Cal-induced mast cell after passively sensitization. Rc pretreatment poorly decreased histamine but leukotrienes decreased by 70% in the OA-induced or by 35% in the Cal-induced mast cell. $Rg_3$ ginsenoside pretreatment increased histamine release without challenging OA or Cal but leukotrienes decreased. These observations indicate that single unit of ginsenosldes may be an important contributor to inhibit the release of histamine and leukotrienes in the guinea pig lung mast cells, that inhibits the PLD-mediated formation of DAG evoked by mast cell activation.