• YAKHAK HOEJI
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• v.45 no.3
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• pp.287-292
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• 2001

To investigate whether phospholipase $A_2$pathway is involved in histamine release of rat peritoneal mast cells, we measured histamine release in the presence of various enzyme inhibitors involved in eicosanoid pathway, such as phospholipase $A_2$, cyclooxygenase and lipoxygenase. Phospholipase $A_2$inhibitors, manoalide and OPC, significantly inhibited histamine release induced by 100 $\mu$M ATP and 1$\mu$g/ml compound 48/80. Cyclooxygenase inhibitors, ibuprofen and indomethacin, significantly inhibited ATP-induced histamine release and lipoxygenase inhibitors, baicalein and caffeic acid, also significantly inhibited. To investigate the involvement of protein kinase in ATP- and compound 48/80-induced histamine release, we observed effects of protein kinase inhibitors on histamine release. Bisindolmaleimide (protein kinase C antagonist) dose-dependently inhibited both ATP and compound 48/80-induced histamine release. Tyrosine kinase inhibitors (methyl 2,5-dihydroxy cinnamate and genistein) dose-dependently inhibited ATP and compound 48/80-induced histamine release. Protein kinase C and tyrosine kinase seem to be involved in histamine release induced by ATP and compound 48/80. These results suggest that phospholipase $A_2$pathway as well as protein kinase C and tyrosine kinase are involved in histamine release of rat peritoneal mast cells by ATP and compound 48/80.

• YAKHAK HOEJI
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• v.54 no.5
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• pp.323-327
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• 2010

Translationally controlled tumor protein (TCTP) activates basophils to release histamine and causes chronic inflammation. It was also reported that TCTP significantly reduced in brain of Alzheimer's Disease and Down Syndrome as compared to normal person, suggesting that TCTP might be involved in cognitive function. We wondered whether TCTP could act as a general inducer in neurotransmitters release in brain. We, therefore, investigated the role of TCTP in PC12 cell line which expressed neuronal properties. We found that TCTP could activate JNK, and the activity was inhibited by pretreatment of dicoumarol, a JNK inhibitor. However, TCTP could not activate ERK that has known to be involved in neurotransmitter release. These suggest TCTP did not participate in neurotransmitter release from PC12 cells, and TCTP might not be a general inducer in neurotransmitter release.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1275-1281
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• 2005

The $G_{q/11}$ protein-coupled receptors, such as muscarinic (M1 & M3) receptors, have been shown to regulate the release of a soluble amyloid precursor protein (sAPP$\alpha$) produced from $\alpha$-secretase processing. However, there is no direct evidence for the precise characteristics of G proteins, and the signaling mechanism for the regulation of $G_{q/11}$ protein-coupled receptor mediated sAPP$\alpha$ release is not clearly understood. This study examined whether the muscarinic receptor-mediated release of sAPP$\alpha$ is directly regulated by $G\alpha_{q/11}$ proteins. The HEK293 cells were transiently cotransfected with muscarinic M3 receptors and a dominant-negative minigene construct of the G protein $\alpha$ subunit. The sAPP$\alpha$ release in the media was measured using an antibody specific for sAPP. The sAPP$\alpha$ release enhancement induced by muscarinic receptor stimulation was decreased by a $G_{q/11}$ minigene construct, whereas it was not blocked by a control minigene construct (the G$\alpha$ carboxy peptide in random order, G$\alpha_{q}$R) or $G\alpha_{j}$ constructs. This indicated a direct role of the $G\alpha_{q/11}$ protein in the regulation of muscarinic M3 receptor-mediated sAPP$\alpha$ release. We also investigated whether the transactivation of the epidermal growth factor receptor (EGFR) by a muscarinic agonist could regulate the sAPP$\alpha$ release in SH-SY5Y cells. Pretreatment of a specific EGFR kinase inhibitor, tyrophostin AG1478 (250 nM), blocked the EGF-stimulated sAPP$\alpha$ release, but did not block the oxoM­stimulated sAPP$\alpha$ release. This demonstrated that the transactivation of the EGFR by muscarinic receptor activation was not involved in the muscarinic receptor-mediated sAPP$\alpha$ release.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.274-283
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• 1996

In this study, the effects of red ginseng components [ginsenosides (total saponins and $Rg_1$) on the function of ryanodine receptor (RyR) -$Ca^{2+}$ release channel complex protein (named as RyR or $Ca^{2+}$ channel), a membrane protein in sarcoplasmic reticulum (SR) of rabbit skeletal muscle were examined at the SR vesicle's level and the molecular levels with Chaps-solubilized and purified $Ca^{2+}$ channel protein and with reconstituted proteoliposomes by dialysis. The results were as follows. 1. The binding of ryanodine known as inhibitor of muscle contraction to the RyR was decreased at the whole range of concentration ($10^2$~$10^7$%) by these two ginseng components. In heavy SR vesicles, Chaps-solubilized and purified $Ca^{2+}$ channel protein, and reconstituted vesicles, its maximal inhibition by total saponins was shown at the concentration of $10^3$, $10^3$%, and $10^5$% respectively, and by gin- senoside $Rg_1}$) each was $10^3$%, $10^3$%, and $10^4$%. 2. The release of $Ca^{2+}$ ion through $Ca^{2+}$ channel in heavy SR vesicles and reconstituted proteoliposomes was increased as a whole by these two ginseng components, and particularly maximal release by both of them was shown at the range of $10^4$~$10^6$%. These results were seemed to be caused by conformational change of $Ca^{2+}$ release channel protein (RyR) by red ginseng components [ginsenosides (total saponins and $Rg_1}$).

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.297.2-297.2
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• 2002

Previous report showed that histamine release by HCI was mediated via reactive oxygen species (ROS) generation in RBL 2H3 cells. To investigate action of protein kinase on histamine release and ROS generation. we observed effects of protein kinase inhibitors on histamine release and ROS generation in RBL 2H3 cells stimulated by HCI HCI dose-dependently increased both histamine release and ROS generation. HCI-induced histamine release was significantly inhibited by bisindolmaleimide (10 ${\mu}$M). DHC (10 ${\mu}$M). , and wortmannin (10 ${\mu}$M), but not by PD098059 (10 ${\mu}$M). ON the other hand. HCI-induced ROS generation was significantly inhibited by DHC (10 ${\mu}$M). but not by bisindolmaleimide(10 ${\mu}$M). wortmannin (10 ${\mu}$M). and PD098059 (10 ${\mu}$M). However KN-62 did not inhibited both. These results showed that involvement of protein kinase in regulation of histamine release and ROS generation may be different and only tyrosine kinase may be associated with regulation of both histamine release and ROS generation in RBL 2H3 cells.

• Journal of Pharmaceutical Investigation
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• v.36 no.2
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• pp.115-121
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• 2006

The aim of this study was to develop new protein/peptide depot system instead of poly(DL-lactic acid-coglycolic acid) (PLGA) microspheres. Pullulan was chemically modified by the addition of acetic anhydride (pullulan acetate; PA) and then investigated as new depot system for protein/peptide delivery. PA microspheres (PAM) with lysozyme as a model protein were prepared by w/o/w double emulsion method. The microspheres had a mean size of 10-50 mm with a spherical shape. The size distributions reduced with increasing the degree of acetylation. The loading efficiency of lysozyme was also increased. Lysozyme aggregation behavior in the microsphere was monitored to estimate the change of protein stability during preparation step. The ratios of protein aggregation in PAMs are lower than that of PLGA microsphere, in particular, PA 5 showed lowest as about 16%. The result indicated that the increase of acetylation suppressed the aggregation of protein. The release profiles of lysozyme from PAMs were significantly different. High acetylation effectively improved lysozyme release kinetics by reducing initial burst release and extending continuous release over a period of time. To check the effect of preservation for structural stability of lysozyme, the activity of lysozyme released from PA 5 was also observed. The activity of lysozyme was maintained almost 100% for 25 day. Therefore, PAM may become to a useful carrier for delivery of protein/peptide drugs, if it will be supported by biocompatibility and biodegradability results.

• KSBB Journal
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• v.22 no.4
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• pp.213-217
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• 2007

It has been reported that hydrophobic additives generally decrease the release rate of protein drugs from drug delivery systems (DDS) and hydrophilic additives increase the release rate. In many cases, however, the addition of hydrophilic molecule is necessary for improving the stability of protein drugs. In the present work, the effects of hydrophilic additives on the release profiles, and micelle formation of protein drug formulations were investigated to develop a novel method for protein drug delivery. For model protein drug, bovine serum albumin (BSA) was employed and several hydrophilic additives were used in the release experiments. Hydrophilic additive D-sorbitol showed the lower release rates of BSA than other hydrophobic additives due to the gel strengthening ability of the additive and the optimum concentration of D-sorbitol was 3 w/v % for the retarded release rate. In addition, it was found that the addition of D-sorbitol was very effective for obtaining homogeneous and stable DDS. The results were discussed in terms of the micelle formation and the micelle structure, i.e., the differences in gel structure and the distribution of drugs in micelles.

• Animal Bioscience
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• v.35 no.2
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• pp.260-271
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• 2022

Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations. Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting. Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05). Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.145-152
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• 1995

The effects and interactions of $4{\beta}-phorbol$ 12,13-dibutyrate(PDB) and polymyxin B(PMB) with adenosine on the electrically-evoked norepinephrine (NE) release were studied in the rat hippocampus. Slices from the rat hippocampus were equilibrated with $^3H-noradrenaline$ and the release of the labelled product, $^3H-NE$, which evoked by electrical stimulation$(3\;Hz,\;2\;ms,\;5\;VCm^{-1},\;rectangular\;pulses)$ was measured. PDB$(0.3{\sim}10\;{\mu}M)$, a selective protein kinase C(PKC) activator, increased the evoked NE release in a dose related fashion while increasing the basal rate of release. And the effects of $1\;{\mu}M$ PDB were significantly inhibited by $0.3\;{\mu}M$ tetrodotoxin(TTX) pretreatment or $Ca^{++}-free$ medium. $PMB(0.03{\sim}1\;mg)$, a specific PKC inhibitor, decreased the NE release in a dose dependent manner while increasing the basal rate of release. Adenosine $(1{\sim}10\;{\mu}M)$ decreased the NE release without changing the basal rate of release, and this effect was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine$(2\;{\mu}M)$, a selective $A_1-receptor$ antagonist, treatment. Also, adenosine effects were significantly inhibited by PDB-and PMB-pretreatment. These results suggest that the PKC plays a role in the NE release in the rat hippocampus and might be participated in a post-receptor mechanism of the $A_1-adenosine$ receptor.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.46-46
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• 2001

Evidence has suggested that an anion channel blocker, 4, 4'-diisothiocyanatostilbene-2, 2' disulfonic acid (DIDS) could trigger Ca release from skeletal sarcoplasmic reticulum (SR) by binding to a 30 kDa SR protein. Since the high molecular weight $Ca^{2＋}$ release channel (CRC)/ryanodine receptor (RyR) is the main SR protein that conducts $Ca^{2＋}$ efflux in skeletal muscles, the relationship between CRC and the 30kDa protein remains to be elucidated.(omitted)