• The Korean Journal of Physiology
• /
• v.19 no.2
• /
• pp.173-187
• /
• 1985

Renal compensatory adaptation caused by ablation of a part of renal mass has long been known in the field of the compensatory renal hypertrophy or hyperplasia. Many reports were found on the chronic mechanisms on the compensatory renal hyperfunction after exclusion of the contralateral kidney. However the mechanism(s) of the acute compensatory hyperfunction after contralateral exclusion has not yet been clarified. In the present experiment, we have tried to prove the possibility of the involvement of the renin-angiotensin system and/or prostaglandin system in the control mechanism of the acute compensatory renal hyperfunction after contralateral kidney exclusion. There were found different responses of the renal hyperfunction by contralateral renal pedicle or ureteral occlusion. Contralateral renal pedicle or ureteral occlusion caused a sustained increases of the urinary volume, sodium and potassium excretion, while the magnitude of the changes was different quantitatively by the maneuvers. Blood collection affected on the acute compensatory renal responses after ureteral as well as renal pedicle occlusion. Plasma prostaglandin $E_2$ level was not changed by the contralateral renal pedicle or ureteral occlusion. Urinary excretion of Prostaglandin $E_2$, the indices of renal prostaglandin biosynthesis, was not changed by the contralateral renal pedicle occlusion, but increased without significance by the contralateral ureteral occlusion. Acute renal compensatory responses after contralateral renal pedicle occlusion were blocked by the pretreatment of indomethacin. Plasma renin activity increased after contralateral ureteral occlusion, but the pattern of the increases was the same as in the time-control group. Plasma renin activity after contralateral renal pedicle occlusion did not change by the time sequence. SQ 20,881, an angiotensin I converting enzyme inhibitor, blunted the contralateral renal responses after the renal pedicle occlusion. Bilateral renal denervation abolished the contralateral renal responses after the renal pedicle occlusion. The above data suggest that there is no direct evidence to support the involvement of the renin-angiotensin system and/or prostaglandin system for the acute compensatory renal hyperfunction after contralateral kidney exclusion, and that the functional changes of the intact kidney may be caused by a humoral substances, or other mechanisms by afferent renal nerve activity originating from the treated kidney.

• The Korean Journal of Physiology
• /
• v.19 no.2
• /
• pp.189-202
• /
• 1985

Enhanced activity of renin-angiotensin-aldosterone system has been suggested as a cause of the high blood pressure in certain forms of experimental hypertension. In spontaneously hypertensive rats, however, increased activity of the system has not been found, and even suppressed renin angiotensin system has been reported in the spontaneously hypertensive rat. In the present experiments it was attempted to explore the possible alteration of the short loop negative feedback control in the hypertensive rat. Experiments have been done in the anesthetized spontaneously hypertensive rats(SHR) as well as in normotensive Wistar and Sprague Dawley rats as control. Responses of the plasma renin activity to the intravenous L-isoproterenol were dose dependent, in both SHR and normotensive control rats. Hypotensive responses to smaller do sea of L-isoproterenol were more accentuated in SHR than in the normotensive control rats. Angiotensin If given intravenously suppressed plasma renin activity in a dose dependent fashion in both groups. However, these suppressive responses were significantly attenuated in SHR as compared with the normotensive control rats. Treatment with angiotensin I-converting enzyme inhibitor did not correct the attenuated responses of the plasma renin activity to angiotensin II in SHR. Intravenous infusion of arginine vasopressin also produced a dose-dependent suppression of plasma renin activity in both groups. The responses to arginine vasopressin were also significantly attenuated to the normotensive control rats. In the sodium-depleted SHR, arginine vasopressin did not suppress plasma renin activity, whereas the suppressive responses to arginine vasopressin in the normotensive control rats were not different from the untreated control rats. These data suggest that there may be a derangement in the short loop negative feedback control of the renin-angiotensin system in spontaneously hypertensive rat.

• YAKHAK HOEJI
• /
• v.35 no.6
• /
• pp.473-482
• /
• 1991

Protein methylase II (S-adenosyl-L-methionine:protein carboxyl-O-methyltransferase; EC 2.1.1.24., PM II) was purified from chicken pancreas by subcellular fractionation, DEAE-cellulose chromatography, QAE-Sephadex A-50 chromatography, Sephadex G-75 chromatography, and Sephadex G-75 rechromatography. The purified PM II gave a single band upon polyarcrylamide gel electrophoresis both in the presence of SDS and in Tris glycine buffer without SDS. The pI value of purified PM II was identified as 5.7 on isoelectric focusing gel. Properties and activities of PM II were studied and the following results were obtained. 1) PM II from chicken pancreas was purified approximately 221-fold with a yield of 1.3%. 2) The purified PM II appear constituted of a single polypeptide chain of a molecular weight 46,800 daltons. 3) Hemoglobin exhibited the highest of methyl-accepting activity among the substrates tested. 4) The purified PM II has a $K_m$ of $4.67{\times}10^{-6}M$ and a $V_{max}$ of 37.5 pmoles of $methyl-^{14}C/min./mg$ enzyme for $SAM^{-14}CH_3$ as methyl donor in the presence of histone type II-As. 5) It is found that S-adenosyl-L-homocysteine is a competitive inhibitor for PM II with $K_i$ value of $3.23{\times}10^{-5}M$.

• Archives of Pharmacal Research
• /
• v.19 no.5
• /
• pp.390-395
• /
• 1996

To investigate whether $AT_{1}$ receptor antagonists are acting by increasing endothelium-de-pendent and -independent relaxation of aortas in normotensive rats, $AT_{1}$ receptor antagonists, losartan and KR-30988, and angiotensin converting enzyme inhibitor, captopril, were orally administered for two weeks (50 mg/kg, b.i.d.). THe blood pressure, heart rate and body weight were not significantly changed by losartan, KR-30988 and captopril compared to the control group. In aortic preparations, the $pD_{2}$ of KR-30988 for ACh-induced relaxation was 8.33 $\pm$ 0.16, significantly (p <0.05) lower than that of control group $(7.71 \pm 0.15)$. ACh-induced relaxation was significantly increased on losartan-treated group (p<0.01) at $10^{-6}$ M of ACh, and in captopril-treated group (p<0.05) at the range of $10^{-7}$ -$10^{-5}$ M of ACh. The $pD_{2}$ values for histamine-induced relaxatio of losartan, KR-30988 and captopril were 5.57 $\pm$ 0.10, 5.85 $\pm$ 0.21 and 5.60 $\pm$ 0.01, respectively, with significant differences in all groups (p<0.01) compared to that of control group (5.13 $\pm$ 0.09). ACh-induced relaxations of aortic preparations were not changed by pretreatment of indomethacin ($10_{-5}$ M), and completely bolcked by pretreatment of L-NAME $(10_{-5}M)$ in all groups. Sodium nitroprusside-induced relaxations were not significantly changed by all drugs tested in this experiments. These results suggest that $AT_{1}$ receptor antagonists, losartan and KR-30988, enhance the endothelium-dependent relaxatio on aortic preparations through the release of, or increase sensitivity, to nitric oxide in nor-motensive rats.

• Journal of Acupuncture Research
• /
• v.23 no.2
• /
• pp.61-72
• /
• 2006

Objectives : Human chondrocytes co-treated with Buthus martensi Karsch herbal acupuncture solution(BMK-HAS) extract produced significantly less NO compared with chondrocytes stimulated with $IL-1{\beta}$ alone Methods : Activation and translocation of and NF-kB DNA binding activity were determined by Western blotting and specific enzyme-linked immunosorbent assay. Results : The inhibition of NO production correlated with the suppression of induction and expression of nuclear factor-kB (NF-kB) and activation protein-1 (AP-1)-dependent gene. BMK-HAS inhibited the activation and translocation of NF-kB to the nucleus, indicating that BMK-HAS inhibits the $IL-1{\beta}-induced$ production of NO in human chondrocytes by interfering with the activation of NF-kB through a novel mechanism. In addition, BMK-HAS reduced prostaglandin E2 (PGE2)production in mouse peritoneal macrophages stimulated with lipopolysaccharide, whereas no influence on the activity of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) or cyclooxygenase-1 (COX-1) was observed. My data, therefore, suggest that BMK-HAS may be a therapeutically effective inhibitor of $IL-1{\beta}-induced$ inflammatory effects that are dependent on NF-kB activation in human OA chondrocytes. Conclusion : The results indicate that BMK-HAS exerts anti-inflammatory effects related to the inhibition of neutrophil functions and of NO and PGE2 production, which could be due to a decreased expression of iNOS and COX-2 through the transcription factors NF-kB and AP-1.

• Journal of Periodontal and Implant Science
• /
• v.26 no.2
• /
• pp.557-566
• /
• 1996

It is known that some natural extracts from plants have a various range of antimicrobial and antiinflammatory activity. There are lots of clinical trials to develop toothpastes containing natural extracts for prevention of dental caries and gingival inflammation. The purpose of this study was to evaluate antimicrobial and antiinflammatory activity of magnolol containing toothpastes and other commercial toothpastes. Eleven kinds oftoothpastes were used. They include magnolol, sanguinarine, Myrrha, Mori radicis cortex,Cimicifugae rhizoma, sodium fluoride, aminocaprolactic acid etc. Six strains of bacteria were used for this test, ego Porphylomonas gingivalis, Prevotellain-termedia, Actinobacillus actinomy cetemcomitans, Streptococcus mutans, Stretococcus sanguis, and Actinomyces species. Antimicrobial activity was determined by an agar dillution method and a broth microdillution method. Antiinflammatory activity was assessed by the inhibition of $PGE_2$ production from gingival fibroblast with the addition of rHIL-1 and centrifuged solution of toothpastes. Control group was only rHIL-1 additive sample. $PGE_2$ enzyme immunoassay systemfAmersham, In. Buckinghamshire, U.K). $PGE_2$ level was measured by ELISA reader with 450 nm, The results from the study revealed that toothpastes containing natural extracts generally had high antimicrobial and antiinflammatory activity. Especially magnolol containing toothpaste showed higher antimicrobial activity than other toothpastes, and sanguinarine containing toothpaste showed particularly high antimicrobial activity in A. actinomicetemcomitans and A. viscosus. In some degree all toothpastes inhibited $PGE_2$ production, but magnolol containing toothpaste was potent inhibitor of $PGE_2$. Sodium chloride containing toothpaste had also effective result. The results suggested that toothpastes containing natural extracts were promising in plaque control and prevention of dental caries and gingivitis.

• Biomedical Science Letters
• /
• v.16 no.2
• /
• pp.105-112
• /
• 2010

Methylprednisolone (MPD) is a synthetic glucocorticoid drug used in treatment of many neurological diseases and neurotraumas, including spinal cord injuries. Little is known of the mechanism of MPD in neuronal cells, particularly the genetic expression aspect. DD-PCR was used in identification of genes expressed during MPD treatment of PC12 cells. We have isolated 3 predicted up- or down-regulated genes, which are differentially expressed in neurons by MPD. One of these genes, USP16 (ubiquitin specific protease 16), is the deubiquitinating enzyme that is up-regulated by MPD in neurons. In order to observe the effect of MPD on USP16 gene expression, PC12 cells were treated under several experimental conditions, including endoplasmic reticulum stress drugs. We have isolated the total RNAs in PC12 cells and detected USP16 and ER related genes by RT-PCR. Because its expression pattern is similar to expression of ER chaperons, USP16 gene expression is strongly associated with unfolded protein response. A meaningful negative effect on each tissue treated by methylprednisolone is not shown in vivo. USP16 gene expression is suppressed by LY294002 (phosphatidylinositol 3-kinase inhibitor), which suggests that USP16 gene expression is regulated by the phosphatidylinositol 3-kinase pathway.

• YAKHAK HOEJI
• /
• v.53 no.4
• /
• pp.222-227
• /
• 2009

Human topoisomerase I (Topo I) plays a pivotal role in cell replication, transcription and repair and, therefore, is an important anti-cancer target. 20S-camptothecin (CPT) is a representative Topo I inhibitor. Compounds belonging to CPT family inhibit the religation step of Topo I-DNA by binding to the DNA cleavage site. Computational docking studies with Surflex-Dock were carried out to investigate the binding modes between Topo I-DNA binary complex structure and the ligand such as 20S-CPT and 9,10-substituted 20S-CPT analogues. The docking results demonstrated that most of the compounds with $IC_{50}$ value under $0.5{\mu}M$ intercalated exactly between the -1 and +1 DNA bases, deeply toward the cleavage site. The complex was stabilized by hydrogen-bonding and hydrophobic interactions with both the enzyme and the DNA. The compounds with $IC_{50}$ value above $0.5{\mu}M$ were poorly docked and did not intercalate. In addition, the docking results confirmed the overall correlation between the $IC_{50}$ values and docking scores, indicating the possible use of the modeling for the prediction of biological activity and design of potential inhibitors.

• Korean Journal of Plant Resources
• /
• v.28 no.6
• /
• pp.682-689
• /
• 2015

Abeliophyllum distichum Nakai (A. distichum) has been reported to exert the inhibitory effect on angiotensin converting enzyme and aldose reductase. Recently, our group found that branch extracts of A. distichum (EAFAD-B) induce apoptosis through ATF3 activation in human colon cancer cells. However, anti-cancer reagents exert their activity through the regulation of various molecular targets. Therefore, the elucidation of potential mechanisms of EAFAD-B for anti-cancer activity may be necessary. To elucidate the potential mechanism of EAFAD-B for anti-cancer activity, we evaluated the regulation of cyclin D1 in human colon cancer cells. EAFAD-B decreased cellular accumulation of cyclin D1 protein. However, cyclin D1 mRNA was not changed by EAFAD-B. Inhibition of proteasomal degradation by MG132 attenuated EAFAD-B-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with EAFAD-B. In addition, EAFAD-B induced cyclin D1 phosphorylation at threonine-286 and the point mutation of threonine-286 to alanine attenuated EAFAD-B-mediated cyclin D1 proteasomal degradation. Inhibitions of both ERK1/2 by PD98059 and NF-κB by a selective inhibitor, BAY 11-7082 suppressed cyclin D1 downregulation by EAFAD-B. From these results, we suggest that EAFAD-B-mediated cyclin D1 downregulation may result from proteasomal degradation through its threonine-286 phosphorylation via ERK1/2-dependent NF-κB activation. The current study provides new mechanistic link between EAFAD-B and anti-cancer activity in human colon cancer cells.

• Archives of Pharmacal Research
• /
• v.27 no.2
• /
• pp.239-245
• /
• 2004

KR-31543, (2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2 -methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran, is a new neuroprotective agent for preventing ischemia-reperfusion damage. This study was performed to identify the metabolic pathway of KR-31543 in human liver microsomes and to characterize cytochrome P450 (CYP) enzymes that are involved in the metabolism of KR-31543. Human liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of two metabolites, M1 and M2. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC/MS/MS analysis with a synthesized authentic standard, and M2 was suggested to be hydroxy-KR-31543. Correlation analysis between the known CYP enzyme activities and the rates of the formation of M 1 and M2 in the 12 human liver microsomes have showed significant correlations with testosterone 6$\beta$-hydroxylase activity (a marker of CYP3A4). Ketoconazole, a selective inhibitor of CYP3A4, and anti-CYP3A4 monoclonal antibodies potently inhibited both N-hydrolysis and hydroxylation of KR-31543 in human liver microsomes. These results provide evidence that CYP3A4 is the major isozyme responsible for the metabolism of KR-31543 to M1 and M2.