• Biomolecules & Therapeutics
• /
• v.15 no.2
• /
• pp.108-117
• /
• 2007

The aim of the present study was to investigate the effect of glibenclamide, a hypoglycemic sulfonylurea, which selectively blocks ATP-sensitive K$^+$ channels, on secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal glands. The perfusion of glibenclamide (1.0 mM) into an adrenal vein for 90 min produced time-dependently enhanced the CA secretory responses evoked by ACh (5.32 mM), high K$^+$ (a direct membrane depolarizer, 56 mM), DMPP (a selective neuronal nicotinic receptor agonist, 100 ${\mu}$M for 2 min), McN-A-343 (a selective muscarinic M1 receptor agonist, 100 ${\mu}$M for 2 min), Bay-K-8644 (an activator of L-type dihydropyridine Ca$^{2+}$ channels, 10 ${\mu}$M for 4 min) and cyclopiazonic acid (an activator of cytoplasmic Ca$^{2+}$-ATPase, 10 ${\mu}$M for 4 min). In adrenal glands simultaneously preloaded with glibenclamide (1.0 mM) and nicorandil (a selective opener of ATP-sensitive K$^+$ channels, 1.0 mM), the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered to the considerable extent of the control release in comparison with that of glibenclamide-treatment only. Taken together, the present study demonstrates that glibenclamide enhances the adrenal CA secretion in response to stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization from the isolated perfused rat adrenal glands. It seems that this facilitatory effect of glibenclamide may be mediated by enhancement of both Ca$^{2+}$ influx and the Ca$^{2+}$ release from intracellular store through the blockade of K$_{ATP}$ channels in the rat adrenomedullary chromaffin cells. These results suggest that glibenclamide-sensitive K$_{ATP}$ channels may play a regulatory role in the rat adrenomedullary CA secretion.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.183-187
• /
• 2015

We use ALLWISE data release W1- and W2-band epoch photometry collected by the Wide-Field Infrared Survey Explorer (WISE) to determine slopes of the period-luminosity relations for RR Lyrae stars in 15 globular clusters in the corresponding bands. We further combine these results with V- and K-band photometry of Galactic field RR Lyrae stars to determine the metallicity slopes of the log $P_F-[Fe/H]-M_K$, log $P_F-[Fe/H]-M_{W1}$, and log $P_F-[Fe/H]-M_{W2}$ period-metallicity-luminosity relations. We infer the zero points of these relations and determine the kinematical parameters of thick-disk and halo RR Lyraes via statistical parallax, and estimate the RR Lyrae-based distances to 18 Local-Group galaxies including the center of the Milky Way.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.5
• /
• pp.87-93
• /
• 2014

For n/m=qm+r, there is no simple divisibility rule for simple m=7 such that is the n multiply by m? This problem can be more complex for two or more digits of m. The Dunkels method has been known for generalized divisibility test method, but this method can not compute very large digits number that can not processed by computer. This paper suggests simple and exact divisibility method for m completely irrelevant n and m of digits. The proposed method sets $r_1=n_1n_2{\cdots}n_l(mod m)$ for $n=n_1n_2n_3{\cdots}n_k$, $m=m_1m_2{\cdots}m_l$. Then this method computes $r_i=r_{i-1}{\times}10+n_i(mod m)$, $i=2,3,{\cdots}k-l+1$ and reduces the digits of n one-by-one. The proposed method can be get the quotient and remainder with easy, fast and correct for various n,m experimental data.

• The Korean Journal of Pharmacology
• /
• v.29 no.2
• /
• pp.275-282
• /
• 1993

Liver microsomal epoxide hydrolase (mEH) is active in the detoxification of epoxide-containing reactive intermediate. Previous studies in this laboratory have shown that thiazole and pyrazine are efficacious inducers of mEH in rats with large increases in mEH mRNA levels (Carcinogensis, Kim et al, 1993). mEH was purified to electrophoretic homogeneity from thiazole-induced rat hepatic microsomes using DEAE-cellulose column chromatography whereas another protein $({\sim}43\;kDa)$ was co-purified with mEH from pyrazine-induced rat hepatic micrsomes (200 mg/kg body weight/day, ip, 3d). The antibody raised from a rabbit against mEH protein purified from thiazole-induced rat hepatic microsomes appeared to specifically recognize mEH protein in rat hepatic microsomes, as assessed by immunoblotting analysis. Immunoblotting analyses revealed a 10- and 7-fold increase in mEH levels in the hepatic microsomes isolated from thiazole- and pyrazine-treated rats, respectively. Moreover, immunoblotting analysis showed cross-reactivity of the mEH antibody with a 43 kDa protein in pyrazine-induced rat hepatic microsomes and with co-purified 43 kDa protein in purified fractions. The ratio between the 43 kDa protein and mEH in pyrazine-induced rat microsomes or in purified fractions was ${\sim}1$ to 15. N-terminal amino acid sequence analysis of both purified rat mEH and 43 kDa protein revealed that 10 out of 12 amino acids in N-terminus of the 43 kDa protein were identical with the mEH sequence with two amino acid residues of the 43 kDa protein undetermined. Either thiazole or pyrazine treatment, however, failed to increase the levels of mEH protein in rabbits while pyrazine caused elevation of the 43 kDa protein in this species, as determined by irnrnunoblotting analysis. These results demonstrated that treatment of rats with either thiazole or pyrazine causes elevation in hepatic mEH expiession whereas pyrazine treatment results in induction of another mEH-related 43 kDa protein and that a distinct species difference exists between rats and rabbits in the induction of mEH by these xenobiotics.

• Korean Journal of Microbiology
• /
• v.34 no.1_2
• /
• pp.64-68
• /
• 1998

In order to identify the characteristics of a Korean isol ate of infectious hematopoietic necrosis virus(IHNV), IHNV-PRT, we have cloned and analyzed cDNAs coding for matrix protein M1 and M2 of the IHNV-PRT. The Ml gene contained 693 bp open reading frame and encoded a protein of 230 amino acids with a molecular weight of 25.9 kDa. The M2 gene had 588 bp open reading frame, encoding a protein of 195 amino acids with a molecular weight of 21.9 kDa. On the deduced amino-acid sequences, M1 and M2 of the IHNV-PRT were found to be 92-93% (M1) and 97% (M2) identical to those of foreign isolates of IHNV. These results indicate that M genes of the IHNV are highly conserved among different strains of IHNV.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.8
• /
• pp.1127-1132
• /
• 2012

Nargenicin $A_1$ is a 28-membered polyketide macrolide, with antibacterial activity against methicillin-resistant Staphylococcus aureus, produced by Nocardia sp. CS682. In this study, the production of nargenicin $A_1$ was improved by enhancing the supply of different biosynthetic precursors. In Nocardia sp. CS682 (KCTC11297BP), this improvement was ~4.62-fold with the supplementation of 30 mM methyl oleate, 4.25-fold with supplementation of 15mM sodium propionate, and 2.81-fold with supplementation of 15 mM sodium acetate. In Nocardia sp. metK18 and Nocardia sp. CS682 expressing S-adenosylmethionine synthetase (MetK), the production of nargenicin $A_1$ was improved by ~5.57-fold by supplementation with 30 mM methyl oleate, 5.01-fold by supplementation with 15 mM sodium propionate, and 3.64-fold by supplementation with 15 mM sodium acetate. Furthermore, supplementing the culture broth of Nocardia sp. ACC18 and Nocardia sp. CS682 expressing the acetyl-CoA carboxylase complex (AccA2 and AccBE) with 30 mM methyl oleate, 15 mM sodium propionate, or 15 mM sodium acetate resulted in ~6.99-, 6.46-, and 5.58-fold increases, respectively, in nargenicin $A_1$ production. Our overall results showed that among the supplements, methyl oleate was the most effective precursor supporting the highest titers of nargenicin $A_1$ in Nocardia sp. CS682, Nocardia sp. metK18, and Nocardia sp. ACC18.

• Korean Journal of Soil Science and Fertilizer
• /
• v.48 no.4
• /
• pp.312-317
• /
• 2015

This study was conducted to evaluate effects of diethylene triamine penta acetic acid (DTPA) treatment on growth of red pepper and nutrient availability to salt accumulated soil in the plastic film house. The treatments were no application (Control), chemical fertilizers (NPK), DTPA (0.06, 0.13, and 0.19 mM) and the half of chemical fertilizers (NPK) with DTPA 0.06 mM. Fruit yield of red pepper showed no significant difference between the treatments (control, NPK, DTPA 0.06 mM, 0.13 mM, except for DTPA 0.19 mM. Red peppers were killed by DTPA 0.19 mM treatment because the high concentration of DTPA was toxic to crop. However, dry mass (stem and leave) and nutrient uptake of red pepper in DTPA 0.06 mM treatment increased significantly compared with those of control. In particular, nutrient uptake of red pepper in DTPA 0.06 mM treatment increased in the order of Fe, Mn, and Zn > Ca and Mg > K, as the magnitude of the stability constants of DTPA. Thus the application of DTPA 0.06 mM was the most effective for the alleviation of nutrient accumulation in the plastic film house soils.

• The Korean Journal of Physiology
• /
• v.20 no.1
• /
• pp.31-41
• /
• 1986

The sufficient myoplasmic $Ca^{++}$ to react with the contractile proteins is necessary to induce contraction of a cardiac muscle. These $Ca^{++}$ for the production of muscle contraction are supplied from the three recognized $Ca^{++}$ sources; internal $Ca^{++}$ release via the sarcoplasmic reticulum(SR), $Ca^{++}$ influx through a gated Ca-channel in the membrane as a Isi, and $Ca^{++}$ transport by the mechanism of Na/ca exchange. However, it is still controversial which $Ca^{++}$ sources act as a main contributor for myoplasmic $Ca^{++}$, Therefore, this study was undertaken in order to examine the $Ca^{++}$ sources for the contraction of frog ventricle. There is evidence that the SR is sparse in frog ventricular fibers, and that T-tubules are absent. Isolated ventricular strips of frog, Rana nigromaculata, were used in this experiment. Isometric tension was recorded by force transducer, and membrane potentials of ventricular muscles were measured through the intracellular glass microelectrodes, which were filled with 3M KCI and had resistance of $30{\pm}50M{\Omega}$. All experiments were performed at room temperature in a tris·buffered Ringer solution which was aerated with 100% $O_2$. Isotonic high K, low Na solution was used to induce K-contracture, K-contracture appeared at the concentration of 20 to 30mM-KCI and was potentiated in parallel with the increase in KCI concentration. The contracture had two components: an initial rapid phasic and a subsequent slow tonic contractile responses. Membrane Potentials measured at normal Ringer solution(2.5mM KCI) was -90 to -100 mV, and decreased linearly as the KCI concentration increased; -55mV at 20mM.KCI, -45mV at 30 mM.KCI, -30 mY at 50 mM.KCI, and -12 mV at 100 mM.KCI. K-contracture was evoked firstly at the membrane potential of -45 mV. The contracture was potentiated by the increase of bathing extracellular $Ca^{++}$ concentration. However, in the absence of $Ca^{++}$ the contracture was almost not induced by 50 mM.KCI solution. Caffeine(20mM) in normal Ringer solution, which is known to release $Ca^{++}$ from SR without substantial effects on the $Ca^{++}$ fluxes across the surface membrane, did not affect membrane potential and also not initiate contracture, but the caffeine in 20 mM-KCI Ringer solution produced a contracture. Above results suggest that the main $Ca^{++}$ source for the K·contracture of frog ventricle is $Ca^{++}$ influx through the voltage-dependent Ca-channel, and that in the K-contracture at the concentration of 100 mM-KCI, the mechanism of Na/ca exchange also partly contributs, in addition to the $Ca^{++}$ influx.

• The Korean Journal of Physiology and Pharmacology
• /
• v.3 no.3
• /
• pp.293-303
• /
• 1999

The influences of specific protein phosphatase and protein kinase inhibitors on the ATP-sensitive $K^+\;(K_{ATP})$ channel-opening effect of pinacidil were investigated in single rat ventricular myocytes using patch clamp technique. In cell-attached patches, pinacidil $(100\;{\mu}M)$ induced the opening of the $K_{ATP}$ channel, which was blocked by the pretreatment with H-7 $(100\;{\mu}M)$ whereas enhanced by the pretreatment with genistein $(30\;{\mu}M)$ or tyrphostin A23 $(10\;{\mu}M)$. In inside-out patches, pinacidil $(10\;{\mu}M)$ activated the $K_{ATP}$ channels in the presence of ATP (0.3 mM) or AMP-PNP (0.3 mM) and in a partial rundown state. The effect of pinacidil $(10\;{\mu}M)$ was not affected by the pretreatment with protein tyrosine phosphatase 1B $(PTP1B,\;10\;{\mu}g\;ml^{-1}),$ but blocked by the pretreatment of protein phosphatase 2A $(PP2A,\;1\;U\;ml^{-1})$. In addition, pinacidil $(10\;{\mu}M)$ could not induce the opening of the reactivated $K_{ATP}$ channels in the presence of H-7 $(100\;{\mu}M)$ but enhanced it in the presence of ATP (1 mM) and genistein $(30\;{\mu}M).$ These results indicate that the $K_{ATP}$ channel-opening effect of pinacidil is not mediated via phosphorylation of $K_{ATP}$ channel protein or associated protein, although it still requires the phosphorylation of serine/threonine residues as a prerequisite condition.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.6
• /
• pp.765-770
• /
• 2014

This study aimed to characterize CTX-M producers of urinary E. coli and K. pneumoniae isolates and to determine the prevalence of plasmid-mediated antimicrobial resistance genes among them. Minimum inhibitory concentrations (MICs) were determined, and PCR and sequencing were performed. Among the 42 (82.3%) E. coli and 24 (77.4%) K. pneumoniae isolates containing $bla_{CTX-M}$, $bla_{CTX-M-14}$ and $bla_{CTX-M-15}$ were detected in 23 and 19 E. coli isolates, respectively, and in 7 and 17 K. pneumoniae isolates, respectively. CTX-M producers of urinary E. coli and K. pneumoniae were resistant to multiple antibiotics and contained other antimicrobial resistance genes. CTX-M-15 producers contained more antimicrobial resistance genes than did CTX-M-14 producers.