• Journal of Life Science
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• v.22 no.2
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• pp.281-284
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• 2012

This study demonstrated that upregulation of gene expression of endoplasmic reticulum (ER) stress chaperones (Bip, ERp29, calnexin, and PDI), ER stress sensors (PERK, ATF6, and Ire1), and cAMP phosphodiesterase 7A1 (cAMP PDE7A1) was induced by ER stresses in FRTL5 cells. While removing A23187 from the culture medium restored upregulation of cAMP PDE7A1 gene expression, removal of thapsigargin did not recover its expression. In addition, cAMP PDE7A1 gene expression was strongly inhibited by treatment with A23187 combined with thyroid stimulating hormone (TSH). The results are the first to show that ER stress induces cAMP PDE7A1 gene expression.

• The Korean Journal of Zoology
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• v.29 no.2
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• pp.79-85
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• 1986

The purpose of the present experiment is to make certain the exsistence of cAMP phosphodiesterase (PDE) in mouse oocytes and confirm its possible role on meiotic resumption. The results showed two types of cAMP in the oocytes with different Michaelis constants (Km) with specific maximum (Vmax); The Km and Vmax of one of two types of PDE were estimated at $0.14 \\pm 0.01 \\muM$ and $0.42 \\pm 0.07$ fmol cAMP hydrolyzed/oocyte/minute, and the other at $14.5 \\pm 2.0 \\muM$ and $2.2 \\pm 0.5$ fmol cAMP hydrolyzed/oocyte/minute. cAMP hydrolysis by PDE was reversibly inhibited in vitro by presence of theophylline or isobutyl-methyl-xanthine (IBMX), which is well known as an inhibitor of oocyte maturation. Consequently, it can be assumed that maturation of oocyte is affected by the high level of intracellular cAMP, and its level is well maintained by presence of PDE inhibitor, such as theophylline and IBMX.

• Archives of Pharmacal Research
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• v.28 no.6
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• pp.675-679
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• 2005

Eight furoquinoline alkaloids were purified from two plants belonging to the Rutaceae family. Kokusaginine. skimmianine, evolitrine, and confusameline were purified from Melicope confusa, and haplopine, robustine, dictamine, and $\gamma$-fagarine from Dictamnus albus. In this study, the eight furoquinoline alkaloids were examined for inhibitory potency against human phos-phodiesterase 5 (hPDE5A) in vitro. DNA encoding the catalytic domain of human PDE5A was amplified from the mRNA of T24 cells by RT-PCR and was fused to GST in an expression vector. GST-tagged PDE5A was then purified by glutathione affinity chromatography and used in inhibition assays. Of the eight alkaloids, $\gamma$-fagarine was the most potent inhibitor of PDE5A, and its single methoxy group at the C-8 position was shown to be critical for inhibitory activity. These results clearly illustrate the relationship between PDE5A inhibition and the methoxy group position in furoquinoline alkaloids.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.873-878
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• 2002

OA-8159, a new Phosphodiesterase (PDE) 5 inhibitor, has exhibited potent erectogenic potential in a penile erection test in rats and anesthetized dogs. In this study, we investigated the mechanism of its erectogenic activity by measuring the activity of OA-8159 against a various PDE isozymes and assessing cGMP and cAMP formation in a rabbit corpus cavernosum in vitro. DA-8159 inhibited the PDE 5 activity in rabbit and human platelets, which the $IC_{50}$ was 5.84$\pm$1.70 nM and 8.25$\pm$2.90 nM, respectively. The $IC_{50}$ of DA-8159 on PDE 1, PDE2, PDE 3 and PDE 6 were 870$\pm$57.4 nM, $101\pm$5 $\mu$M, 52.0$\pm$3.53 $\mu$M and 53.3$\pm$2.47 nM, respectively. This suggests that DA-8159 is a potent, highly selective, competitive inhibitor of PDE 5-catalyzed cGMP hydrolysis. The rates of cGMP hydrolysis catalyzed by human platelets-derived PDE 5 as a function of the cGMP concentration (5~100 nM) and two-fixed DA-8159 concentration (11.3 and 18.8 nM) were investigated in order to characterize the mode of PDE 5 inhibition by DA-8159. DA-8159 increased the apparent 4K_{m}$ value for cGMP hydrolysis but had no effect on the apparent $V_{max}$, indicating a competitive mode of inhibition. DA-8159 increased the cGMP concentrations in the rabbit corpus cavernosum dose dependently. In the presence of sodium nitroprusside (SNP), DA-8159 significantly sti\mulated the accu\mulation of cGMP when compared to the control level. This indicated that the enhancement of a penile erection by DA-8159 involved the relaxation of the cavernosal smooth \muscle by NO-sti\mulated cGMP accu\mulation. In conclusion, DA-8159 is a selective inhibitor of PDE 5-catalyzed cGMP hydrolysis and the enhancement of a penile erection by DA-8159 is mediated by the relaxation of the cavernosal smooth \muscle by the NO-sti\mulated cGMP accu\mulation.

• Analytical Science and Technology
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• v.29 no.1
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• pp.10-18
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• 2016

Phosphodiesterase (PDE) plays an important role in cAMP-mediated signaling within cells. We previously showed that the long-form of Aplysia PDE4 (ApPDE4) was localized in the plasma membrane and the presynaptic terminal in Aplysia sensory neurons, and the 16 N-terminal amino acid was sufficient for this targeting process. In this study, we characterized the cellular localization of various ApPDE4 mutants. We first identified the roles of each amino acid within the group of 16 N-terminal amino acids of long-form ApPDE4. As a result, we were able to identify various mutants that were localized to both the plasma membrane and the Golgi complex, Golgi only, or both the endoplasmic reticulum (ER) and the Golgi complex. To examine the role of palmitoylation on the cellular localization of ApPDE4 mutants, 2-bromo palmitate (2-BR) was used as a treatment. As a result, in the presence of 2-BR, the plasma membrane targeting of many mutants was impaired, indicating that palmitoylation was involved in the plasma membrane targeting of the mutants. We also found that PI4P play crucial roles in the Golgi targeting of (N16,C3S/VV/G)-mRFP, L(N16,C3S/LFS/R)-mRFP, and L(N16,EPL/R)-mRFP.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.46.3-46
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• 2002

Most of the process control algorithms in practice are based on the finite dimensional control theory. However, many chemical processes are described by partial differential equations (PDE's) and are infinite dimensional in nature due to spatial variation. Especially when the convection is dominant and thus diffusion can be ignored, chemical processes that are described by a system of first order hyperbolic PDE's. Such processes include tubular reactors, fixed bed reactors and pressure swinging adsorption. Conventionally such infinite dimensional systems described by PDE's are controlled by finite dimensional controllers that are designed through finite dimensional reduction of the process m...

• The Korean Journal of Pharmacology
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• v.29 no.2
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• pp.253-261
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• 1993

Possible changes in the role of insulin-sensitive cyclic nucleotide phosphodiesterase(PDE) in mediating the antilipolytic action of insulin were investigated in adipocytes from streptozotocin-induced diabetic rats. Isolated adipocytes prepared from epididymal adipose tissue were incubated, with or without insulin, at $37^{\circ}C$ for 15 min following pretreatment with various drugs or toxins, and three (plasma membranes, microsomal membranes, and cytosol) fractions prepared by differential centrifugation were then assayed for cAMP phosphodiesterase activity. The PDE activities only in the crude microsomal (P2) fractions were activated by insulin both in diabetic and control rats. The basal PDE activities in P2 fractions of adipocytes from diabetic rats were higher than those from control rats, although the maximal effects observed at 2 nM of insulin, $100\;{\mu}M$ of isoproterenol or the combination of both were not significantly different from each other. The insulin-stimulated PDE activities in P2 fractions of adipocytes from diabetic rats were not changed by PIA, a $A_{1}$ adenosine receptor agonist, whereas they were decreased to the basal PDE activities in those from control rats. In addition, the adipocytes from diabetic rats showed an increased sensitivity to pertussis toxin compared to those from controls. There were no differences between diabetic and control rats in the sensitivity of adipocytes to cholera toxin. These data indicate that the impaired signalling through inhibitory receptors such as adenosine receptors in adipocytes from streptozotocin-induced diabetes relates to the loss or the decreased function of $G_i$ proteins, and leads to the increased activity of the insulin-dependent PDE at the basal states.

• East Asian mathematical journal
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• v.35 no.5
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• pp.547-557
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• 2019

This paper is concerned with the necessary conditions for optimal control problem governed by some ODE-PDE systems. That is, we obtain the necessary conditions for optimal control by showing the differentiability of the solution with respect to the control.

• Journal of Photoscience
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• v.9 no.2
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• pp.275-277
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• 2002

We have recently found that a detergent-resistant raft like membrane (DRM) can be prepared from bovine rod outer segment membranes as a low-density buoyant fraction in sucrose density gradient ultracentrifugation. G protein (transducin) and its effector enzyme (phosphodiesterase: PDE) drastically change their affinities to DRM in the process of phototransduction. We report here that the recruitment of transducin and/or $^2$PDE to DRM has close relationship with their states in signal transduction. Active T$\alpha$/PDE-complex has a high affinity to DRM, whereas inactive transducin, or inactive PDE are excluded from DRM. Active T$\alpha$/PDE-complex seems to bind to a GTPase activating protein (GRS9) in multi- protein complexes localized on DRM. Physiological significance of the multi-protein complex on the raft-like membrane in vertebrate phototransduction would be discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1349-1353
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• 2003

CEMTool is a command style design and analyzing package for scientific and technological algorithm and a matrix based computation language. In this paper, we present a compiler based approach to the implementation of the command mode generalized PDE solver in CEMTool. In contrast to the existing MATLAB PDE Toolbox, our proposed FEM package can deal with the combination of the reserved words such as "laplace" and "convect". Also, we can assign the border lines and the boundary conditions in a very easy way. With the introduction of the lexical analyzer and the parser, our FEM toolbox can handle the general boundary condition and the various PDEs represented by the combination of equations. That is why we need not classify PDE as elliptic, hyperbolic, parabolic equations. Consequently, with our new FEM toolbox, we can overcome some disadvantages of the existing MATLAB PDE Toolbox.