• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.6
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• pp.341-347
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• 2017

To investigate the effect of Corni Fructus(CF) water extracts on the relaxation of the corpus cavernosum, organ bath studies, histochemical and immunohistochemical methods were used and obtained the following results. In the organ bath study, the maximal contraction of the corpus cavernosum tissue by PE showed a significant relaxation effect at $3.0mg/m{\ell}$ of CF water extract. When ${\text\tiny{L}}$-NNA was pretreated corpuscular relaxation effect of CF water extract was significantly inhibited compared without ${\text\tiny{L}}$-NNA pretreatment. In $Ca^{2+}$-free solution, the increase of contraction due to $Ca^{2+}$ influx significantly inhibited in the pretreatment compared with no pretreatment of CF water extract. Histochemical and immunohistochemical studies showed that the ratio of smooth muscle to collagen fiber was increased in the CF group compared to the PE group in the corpus cavernosum, and the eNOS positive reaction increased and the PDE5 positive reaction decreased. These results suggest that CF extract has increased NO production through activation of eNOS and inhibited the action of PDE5 to block the extracellular $Ca^{2+}$ influx, thereby relaxing the smooth muscle of the corpus cavernosum.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.3
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• pp.149-154
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• 2006

Selective inhibition of phosphodiesterase (PDE) 5 opened a new therapeutic approach for cardiovascular disorders. Therefore, the effect of PDE5 inhibition on the cardiac function should thoroughly be defined. The purpose of the present study was to define the effects of sildenafil, a selective inhibitor of PDE5, on the atrial cGMP efflux, atrial dynamics, and the release of atrial natriuretic peptide (ANP). By perfusing rabbit left atria to allow atrial pacing, changes in atrial stroke volume and pulse pressure, transmural extracellular fluid translocation, cGMP efflux, and ANP secretion were measured. SIN-I, an NO donor and soluble (s) guanylyl cyclase (GC) activator, and C-type natriuretic peptide (CNP), an activator of particulate (p) GC activator, were used. Sildenafil increased basal levels of cGMP efflux slightly but not significantly. Sildenafil in a therapeutic dose increased atrial dynamics (for atrial stroke volume, $2.84{\pm}1.71%$, n=12, vs $-0.71{\pm}0.86%$, n=21; p<0.05) and decreased ANP release ($-9.02{\pm}3.36%$, n=14, vs $1.35{\pm}3.25%$, n=23; p < 0.05), however, it had no effect on the SIN-1- or CNP-induced increase of cGMP levels. Furthermore, sildenafil in a therapeutic dose accentuated SIN-1-induced, but not CNP-induced, decrease of atrial pulse pressure and ANP release. These data indicate that PDE5 inhibition with sildenafil has a minor effect on cGMP levels, but has a distinct effect on pGC-cGMP- and sGC-cGMP-induced contractile and secretory function.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.466-477
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• 1994

PEG 600-diglycidyl ethers(PDE) were synthesized using $BF_3$ catalyst by the reaction of epichlorohydrin and PEG 600 which is known to have the hygroscopicity, softening property, and antistatic property. Water-soluble long chain polyamines(PDET) were synthesized by coreaction of PDE and triethylenetetramine which is high conductive aliphatic amine curing agent. To prevent the gelation of the PDET and increase the water-solution stability, water-soluble quaternary ammonium polyamines were synthesized by cationation of PDET with acetic acid. Antistatic agents PDET-2A, PDET-5A, PDET-6A, PDETA-2A and PDETA-4A were prepared by the mixing of PDET-2, PDET-5, PDET-6, PDETA-2 and PDETA-4 with water. Synthesized antistatic agents were treated on PET textiles with and without resin. Then surface electrical resistivity and half life characteristics value were tested. As the results there were no remarkable decreasing changes in antistatic abilities of the textiles treated with PDETA-2A and PDETA-4A after 50 times washing. So PDETA-2A and PDETA-4A were proved to be durable antistatic agents. Surface electrical resistivity of the textiles treated with PDETA-2A and PDETA-4A before washing were $1{\times}10^7{\Omega}$ and $2{\times}10^7{\Omega}$, respectively, and half life characteristics values were 0.8sec and 1.1sec, respectively. Therefore PDETA-2A and PDETA-4A were proved to be good antistatic agents.

• Biomolecules & Therapeutics
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• v.28 no.4
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• pp.328-336
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• 2020

Diabetes mellitus affects the colonic motility developing gastrointestinal symptoms, such as constipation. The aim of the study was to examine the role of intracellular signaling pathways contributing to colonic dysmotility in diabetes mellitus. To generate diabetes mellitus, the rats were injected by a single high dose of streptozotocin (65 mg/kg) intraperitoneally. The proximal colons from both normal and diabetic rats were contracted by applying an electrical field stimulation with pulse voltage of 40 V in amplitude and pulse duration of 1 ms at frequencies of 1, 2, 4, and 6 Hz. The muscle strips from both normal rats and rats with diabetes mellitus were pretreated with different antagonists and inhibitors. Rats with diabetes mellitus had lower motility than the control group. There were significant differences in the percentage of inhibition of contraction between normal rats and rats with diabetes mellitus after the incubation of tetrodotoxin (neuronal blocker), atropine (muscarinic receptor antagonist), prazosin (α₁ adrenergic receptor antagonist), DPCPX (adenosine A1 receptor antagonist), verapamil (L-type Ca²⁺ channel blocker), U73122 (PLC inhibitor), ML-9 (MLCK inhibitor), udenafil (PDE₅ inhibitor), and methylene blue (guanylate cyclase inhibitor). The protein expression of p-MLC and PDE₅ were decreased in the diabetic group compared to the normal group. These results showed that the reduced colonic contractility resulted from the impaired neuronal conduction and decreased muscarinic receptor sensitivity, which resulted in decreased phosphorylation of MLC via MLCK, and cGMP activity through PDE₅.

• Mass Spectrometry Letters
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• v.3 no.2
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• pp.50-53
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• 2012

After success of sildenafil for the treatment of erectile dysfunction, a large number of its analogues have been approved from FDA. Recently, the illegal dietary supplements which include sildenafil, vardenafil, tadalafil, or analogues of these drugs as ingredient have been widely distributed. Therefore, the determination of the residue of synthetic phosphodiesterase- 5 (PDE-5) inhibitors in dietary supplements is highly required due to indiscriminate and unintentional overdose caused nausea, chest pains, fainting and irregular heartbeat. In this paper, we report a rapid and sensitive analytical method for the simultaneous determination of nine phosphodiesterase-5 inhibitors by liquid chromatography-high resolution mass spectrometry. The present method was found to be accurate and reproducible with 40 ${\mu}g$/g of the limit of quantification for the nine PDE-5 inhibitors. The developed method can be successfully applied to the analysis of the seven illegal dietary supplements.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.3-12
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• 2000

The multi-region model, to describe preferential flow, is an equation representing solute transport in soils by dividing soil into numerous pore groups and using the hydraulic properties of the soil. As the model partial differential equation (PDE) is solved numerically with finite difference methods. a modified equivalent partial differential equation(MEPDE) of the partial differential equation of the multi-region model is derived to analyze the accuracy and consistency of the solution of the model PDE and the Von Neumann method is used to analyze the stability of the finite difference scheme. The evaluation obtained from the MEPDE indicated that the finite difference scheme was found to be consistent with the model PDE and had the second order accuracy The stability analysis is performed to analyze the model PDE with the amplification ratio and the phase lag using the Von Neumann method. The amplification ratio of the finite difference scheme gave non-dissipative results with various Peclet numbers and yielded the most high values as the Peclet number was one. The phase lag showed that the frequency component of the finite difference scheme lagged the true solution. From the result of the stability analysis for the model PDE, it is analyzed that the model domain should be discretized in the range of Pe < 1.0 and Cr < 2.0 to obtain the more accurate solution.

• BMB Reports
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• v.31 no.2
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• pp.170-176
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• 1998

Phosphatidylethanolamine N-methyltransferase (PEMT) is known to be a membrane-associated protein. However, cytosolic PEMT was detected when sufficient amounts of exogenous phospholipids were added in the incubation media. The methylation of phospholipids was measured by the incorporation of the $[^3H]-methyl$ group from S-adenosylmethionine and the methylated phospholipids were analyzed by thinlayer chromatography. The essence of the assay condition for the cytosolic enzyme was the inclusion of 200 ${\mu}g$ of each substrate, phosphatidylethanolamine (PE), phosphatidyl N-monomethylethanolamine (PME) and phosphatidyl N,N-dimethylethanolamine (PDE), in the reaction mixture of 100 ${\mu}l$. The subcellular fractionation of brain PEMT activities revealed that approximately 38.1 % for PME, 39.5% for PDE, and 22.4% for PC formation was present in the cytosolic fraction. The general properties of cytosolic PEMT were characterized and compared with those of neuronal nuclei PEMT.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.725-727
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• 2009

Lowering the dielectric constant is one of the important issues for the efficiency and the power consumption in the plasma display panel (PDP) industry. This study examined the effect of the addition of ceramic filler (up to 10% of crystalline and amorphous silica, respectively) to a $B_2O_3$-ZnO- $P_2O_5$ glass matrix on the dielectric, coefficient of thermal expansion, etching behaviors and residual stress for the barrier ribs in plasma display panels. The dielectric constant of barrier ribs is affected by containing two types of $SiO_2$ filler for the barrier rib composition in PDP.

• East Asian mathematical journal
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• v.38 no.5
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• pp.603-610
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• 2022

In [6, 7] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities. They consider the Poisson equations with homogeneous boundary conditions, compute the finite element solutions using standard FEM and use the extraction formula to compute the stress intensity factor(s), then they posed new PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor(s), which converges with optimal speed. From the solution they could get an accurate solution just by adding the singular part. They considered a partial differential equation with the input function f ∈ L²(Ω). In this paper we consider a PDE with the input function f ∈ H¹(Ω) and find the corresponding singular and dual singular functions. We also induce the corresponding extraction formula which are the basic element for the approach.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.249.2-250
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• 2002

Tolerance and pharmacolinetics after single-dose administration of DA-8159, a new selective PDE5 inhibitor under phase 1 study, were examined in 42 healthy male volunteers in a six-period, double-blinded placebo-controlled study. Participants received single oral tablet of DA-8159 (12.5 to 300mg) or placebo. Adverse effects and pharmacokinetic parameters were monitored during experiments. DA-8159 was well tolerated and the frequency of adverse events was dose-related. (omitted)