• The Korean Journal of Pharmacology
• /
• v.13 no.1 s.21
• /
• pp.29-33
• /
• 1977

Effects of 50% glucose solution on pancreatic exocrine function were studied in rat, rabbit and cat. The alterations during the resting state, the continuous intravenous infusion of secretin and the infusion of secretin with CCK-PZ were determined. 1) No change of pancreatic secretion in rat was observed by intragastric administration of the hypertonic glucose solution. 2) Intragastric administration of the hypertonic glucose solution in rabbit produced the inhibitory effect on pancreatic secretion during secretion infusion. 3) While secretin with CCK-PZ were infused continuously, intragastric administration of the hypertonic glucose solution revealed the marked inhibitory effect on pancrcreatic secretion in cat. Oral administration of the hypertonic glucose solution produced no significant inhibition in the resting gland but markedly depressed the pancreatic flow and enzyme concentration in the secretin or CCK-PZ stimulated gland. It is felt that the inhibitory response of exocrine pancreas induced by intragastric hytertonic glucose solution is resulted in interaction between secretory hormone and gastric mucosal factor possibly enteroglucagon.

• Archives of Pharmacal Research
• /
• v.21 no.6
• /
• pp.657-663
• /
• 1998

The enzyme responsible for the synthesis of nitric oxide (NO) from L-arginine in mammalian tissues is known as nitric oxide synthase (NOS) (EC.1.14.13.39). In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat pancreatic acinar cells. Treatment of rat pancreatic acinar cells with cholecystokinin-octapeptide (CCK-OP) resulted in an increase in the arginine conversion to citrulline, the amount of $NO_X$, the release of amylase, and the level of CGMP. Especially, CCK-OP-stimulated increase of arginine to citrulline transformation, the amount of $NO_X$, and CGMP level were completely counteracted by the inhibitor of NOS, NG-monomethyl-L-arginine (MMA), by contrast, that of amylase release was partially reduced. Furthermore, MMA-induced decrease of NOS activity and amylase release showed dose-dependent pattern. The data on the time course of CCK-OP-induced citrulline formation and CGMP rise indicate that NOS and guanylate cyclase were activated by treatment of CCK-OP. However, the mechanism of agonist-stimulated guanylate cyclase activation in acinar cells remains unknown. Therefore, activation of NOS is one of the early events in receptor-mediated cascade of reactions in pancreatic acinar cells and NO, not completely, but partially mediate pancreatic enzyme exocrine secretion.

• BMB Reports
• /
• v.30 no.6
• /
• pp.379-384
• /
• 1997

The effects of several ions on the specific activity and isozyme patterns of cellular and secretory isoperoxidases were studied in suspension-cultured cells of rice (Oryza sativa L.). Peroxidase release into the culture medium occurred in the absence of added calcium. The addition of calcium ion greatly stimulated the secretion of cationic isoperoxidases such as C2 and C3 into the medium: a maximum 11 fold increase of secretions occurred in the presence of 5 mM $CaCl_2$, and the secretion was accomplished within 1 hour after the addition of $CaCl_2$. About a 10 fold increase of the peroxidase secretion into the medium did occur with 0. 5% NaCl, whereas cellular isoperoxidase levels were reduced notably. About a 6 fold increase of the specific activity of cellular isoperoxidase was found in 5 mM $NiCl_2$-treated cell, while $NiCl_2$ had no effect on the secretion of peroxidase into the medium. Various concentrations of KCl did not change peroxidase secretion, but 5 mM $ZnCl_2$ reduced peroxidase secretion greatly. The major secretory isoperoxidases stimulated by $CaCl_2$, NaCl and cellulase were composed of cationic isoperoxidases C2 and C3, which were found to be localized in the cell wall of rice by examination of the enzyme in the protoplast. Furthermore, the secretion rates of secretory isoperoxidases were increased rapidly when cellulase was treated in the absence of the osmotic stabilizer of 0.4 M mannitol. These results suggest that the stimulations of secretory isoperoxidase levels seem to be due to the stimulation of secretion into the culture medium of rice.

• Journal of Life Science
• /
• v.11 no.1
• /
• pp.42-46
• /
• 2001

Subtilisin YaB, produced by alkalophilic Bacillus strain YaB, is an extracellular alkaline serine protease having 55% homology to subtilisin BPN'. It is synthesized as a 378-amino acid preproenzyme and secreted into the culture medium as a 265-amino acid mature protease. To examine the role of pro-sequence for the secretion of subtilisin YaB, we have studied the expression, in Bacillus subtilis, of a mutant preprosubtilisin YaB in which active site Ser214 is substituted with Cys. The use of a six protease-deficient strain, WB600, was required for its efficient production. The prosubtilisin YaB, thus produced, was indeed secreted into the culture medium and was processed to its mature form upon treatment with exogenously added active subtilisin YaB. From these results, we have concluded that the processing of pro-sequence is not essential for the secretion of the enzyme.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.3
• /
• pp.887-892
• /
• 2004

Cheonggeumganghwa-tang(CGT) has been used for the purpose of prevention and treatment of bronchial asthma and allergic asthma in Korea. To investigate the biological effect of CGT, the author examined cytotoxicity and inflammatory cytokines secretion with human mast cell line, HMC-1. HMC-1 was stimulated with phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. CGT by itself had no effect on viability of HMC-1. The effects of CGT on the secretion of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 from HMC-1 were evaluated with enzyme-linked immunosorbent assay (ELISA). CGT (1 ㎎/㎖) inhibited PMA plus A23187 -induced TNF-α and IL-6 secretion, by 93.86 ± 2.05%, 68.69 ± 2.86%, respectively. CGT also inhibited the NF-κB (p50) expression. Taken together, these results suggest that CGT inhibit the production of inflammatory cytokines in HMC-1 cells through blockade of NF-κB activation.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.7
• /
• pp.963-977
• /
• 2015

The well-characterized gram-positive bacterium Bacillus subtilis is an outstanding industrial candidate for protein expression owing to its single membrane and high capacity of secretion, simplifying the downstream processing of secretory proteins. During the last few years, there has been continuous progress in the illustration of secretion mechanisms and application of this robust host in various fields of life science, such as enzyme production, feed additives, and food and pharmaceutical industries. Here, we review the developments of Bacillus subtilis as a highly promising expression system illuminating strong chemical- and temperatureinducible and other types of promoters, strategies for ribosome-binding-site utilization, and the novel approach of signal peptide selection. Furthermore, we outline the main steps of the Sec pathway and the relevant elements as well as their interactions. In addition, we introduce the latest discoveries of Tat-related complex structures and functions and the countless applications of this full-folded protein secretion pathway. This review also lists some of the current understandings of ATP-binding cassette transporters. According to the extensive knowledge on the genetic modification strategies and molecular biology of Bacillus subtilis, we propose some suggestions and strategies for improving the yield of intended productions. We expect this to promote striking future developments in the optimization and application of this bacterium.

• YAKHAK HOEJI
• /
• v.35 no.4
• /
• pp.341-347
• /
• 1991

It was reported that protein carboxymethylation is involved in amylase secretion of parotid gland by isoproterenot. It was also suggested that a small part of the total cellular protein carboxymethylation is directly involved in pancreatic enzyme secretion. On the contrary, other authors reported that there is no relationship between protein carboxymethylation and secretion in pancreas and parotid gland. In recent study, it was proposed that a methyl acceptor protein plays a limited modulatory role in the coupling of cytosolic $Ca^{++}$ accumulation and exocytosis. In this study, the effects of cholinergic and adrenergic agents on the activities of protein methylase II in pancreatic tissues were examined to test the relationship between protein methylation and pancreatic secretion. The results are as follows. The activity of amylase was slightly increased at the concentration of $10^{-5}$ M of isoproterenol and norepinephrine. The activities of protein methylase I and II were decreased by isoproterenol and norepinephrine, but the activities of protein methylase III were hardly changed. The cholinergic stimulants acetylcholine and carbachol at a concentration of $10^{-5}$ M increased the activities of protein methylase I and decreased the activitiy of protein methylase III compared with control.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.4
• /
• pp.791-807
• /
• 2017

The type II secretion system (T2SS), which transports selected periplasmic proteins across the outer membrane, has rarely been studied in nonpathogens or in organisms classified as Betaproteobacteria. Therefore, we studied Cupriavidus metallidurans (Cme), a facultative chemilithoautotroph. Gel analysis of extracellular proteins revealed no remarkable differences between the wild type and the T2SS mutants. However, enzyme assays revealed that native extracellular alkaline phosphatase is a T2SS substrate, because activity was 10-fold greater for the wild type than a T2SS mutant. In Cme engineered to produce three Ralstonia solanacearum (Rso) exoenzymes, at least 95% of their total activities were extracellular, but unexpectedly high percentages of these exoenzymes remained extracellular in T2SS mutants cultured in rich broth. These conditions appear to permit an alternative secretion process, because neither cell lysis nor periplasmic leakage was observed when Cme produced a Pectobacterium carotovorum exoenzyme, and wild-type Cme cultured in minimal medium secreted 98% of Rso polygalacturonase, but 92% of this exoenzyme remained intracellular in T2SS mutants. We concluded that Cme has a functional T2SS despite lacking any abundant native T2SS substrates. The efficient secretion of three foreign exoenzymes by Cme is remarkable, but so too is the indication of an alternative secretion process in rich culture conditions. When not transiting the T2SS, we suggest that Rso exoenzymes are probably selectively packaged into outer membrane vesicles. Phylogenetic analysis of T2SS proteins supports the existence of at least three T2SS subfamilies, and we propose that Cme, as a representative of the Betaproteobacteria, could become a new useful model system for studying T2SS substrate specificity.

• The Korean Journal of Pharmacology
• /
• v.29 no.2
• /
• pp.237-244
• /
• 1993

The effect of nicotine on the secretion of $[Met^{5}]-enkephalin$ (ME) in addition to proenkephalin A (proENK) mRNA levels and effects of indomethacin, nordihydroguaiaretic acid (NDGA), and captopril on nicotine-induced responses were studied in bovine adrenal medullary chromaffrin (BAMC) cells. Long-term exposure of BAMC cells to nicotine at a concentration of $10{\mu}M$ significantly increased proENK mRNA level and the secretion of ME into the medium. Treatment of BAMC cells with NDGA (a lipoxygenase inhibitor, $10{\mu}M$), indomethacin (a cycloooxygenase inhibitor) or captopril (an angiotensin converting enzyme inhibitor) alone did not affect ME secretion and proENK mRNA levels. The pretreatment of BAMC cells with NDGA inhibited the increased ME secretion and proENK mRNA level induced by nicotine. However, indomethacin and captopril did not affect nicotine-induced responses. Our results indicate that neuronal regulations of ME secretion and proENK mRNA level induced by nicotine in BAMC cells are in part mediated by a lipoxygenase-but not cyclooxygenase-and endogenous renin-angiotensin pathway.

• The Journal of Pediatrics of Korean Medicine
• /
• v.18 no.2
• /
• pp.31-48
• /
• 2004

Objective : KagamJwagwiEum(KJE) has been used for the purpose of prevention and treatment of bronchial asthma and allergic asthma in Korea. To investigate the biological effect of KJE, the author examined cytotoxicity and inflammatory cytokines secretion with human leukemic mast cell line, HMC-1. Methods: HMC-1 was stimulated with phorbol 12-myristate 13-acetate(PMA) and calcium ionophore A23187. KJE by itself had no effect on viability of HMC-l. The effects of KJE on the secretion of tumor necrosis $factor-alpha(TNF-{\alpha})$, interleukin(IL)-6 and IL-8 from HMC-1 were evaluated with enzyme-linked immunosorbent assay. Results : KJE inhibited PMA plus A23187-induced $TNF-{\alpha}$ and IL-6 secretion. But KJE had no effect IL-8 secretion: KJE had immunoregulatory effects on cytokines, increased secretion of NO and $TNF-{\alpha}$ but did not effect IL-12 secretion when the cells were primed and trigged with $IFN-{\gamma}$ in the peritoneal macrophages of C57BL/6 mice. Conclusions : Taken together, these results suggest that KJE inhibit the production of inflammatory cytokines in HMC-1 cells and activate macrophages.