• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.35 no.1
• /
• pp.58-64
• /
• 1990

This study was conducted to investigate the interaction effect of a new plant growth regulator brassinolide and auxins using several bioassay methods such as rice lamina inclination test, oat coleoptile segment growth test and radish hypocotyl elongation test. For rice lamina inclination test, the antagonistic response showed at low concentration combinations of homobrassinolide and auxins (IAA and 2,4-D), while the combinations of high concentration responsed mostly synergistic or additive effects, IAA was generally higher than 2,4-D for combination effect with homobrassinolide. For oat coleoptile segment growth test, the synergistic effect showed at IAA concentrations less than 0.1ppm while additive response exhibited above 0.3ppm regardless of homobrassinolide concentrations. In radish hypocotyl elongation test, the interaction response varied with cotyledon. The sections removed cotyledon showed mostly antagonistic effects, except for combination of homobrassinolide with IAA 3ppm. Interaction responses were Quite different from bioassay methods, particularly using experimental materials: antagonistic responses were usually shown at the section that attached growing point while these for sections that removed growing point were responded synergistic or additive effect due to unstable endogenous hormones.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1977.10a
• /
• pp.193-194
• /
• 1977

대사길항물질에 의한 미생물의 생육조해는 그 시험계에 대사검질을 첨가하므로써 회복되는 것이며 최소검정배지에 대한 대사조해에 대사물질, 예로 amino산, 핵산등을 첨가해서 조해회복을 screening하므로써 그들 물질(amino산 핵산등)의 대사에 길항하는 새로운 화합물을 발견할수가 있다. 이러한 견지에서 고선균이 생산하는 새로운 amino 산대사 길항물질이 탐색을 목적으로하여 screening한 결과 토양에서 새로이 분이한 Streptomyces 1주의 탑양액중에 L-threonine에만 결항작용을 나타내는 물질의 존재를 확인하고 유사구조를 갖는 2종의 tripeptide 대사조항물질의 단이에 성공하였으며 이들을 plumbemycin A 및 B라고 명명하였다.(중략)

• The Korean Journal of Pharmacology
• /
• v.23 no.2
• /
• pp.101-111
• /
• 1987

We investigated the binding properties of $(^3H)$ QNB and $(^3H)$ NMS to mAchR to elucidate the characterstics of mAchR in rat brain by using two different preparations (homogemates & intact brain cell aggregates). The binding properties of both ligands demonstrated high affinity and saturability in both experiments, however $(^3H)$ QNB showed a significantly higher maximal binding capacity than tha ot $(^3H)$ NMS 1. In rat brain homogenates; Displacement of both lignands with several mAchR antagonists resulted in competition curves in accoradnce with the law of massaction for QNB, atropine & scopolamine in thie preparation, also a similar profile was found for the quaternary ammonium analogs of atropine & scopolamine (methyl atropine & methylscopolamine) when $(^3H)$ NMS was used to label the receptors in rat brain. But when these hydrophillic antagonists were used to displace $(^3H)$ QNB, they showed interaction with high- and low-affinity binding sites in brain homogenates. Pirenzepine, the nonclassical mAchR antagonist, was able to displace both ligands from binding sites in this preparation. 2. In intact rat brain cell aggregates; Intact bain cell aggregates were used to elucidate the binding characteristics of $(^3H)$ NMS to mAchR in rat. The magnitude of binding of this ligand was related linearly to the amount of cell protein in the binding assay with a high ratio of total to nonspecific binding. mAchR antagonists displaced specific $(^3H)$ NMS binding according to the law of mass-action, while it was possible to resolve displacement curves using mAchR agonist into high-& low-affinity component. 3. Our results indicate that more hydrophilic receptor ligand $(^3H)$ QNB, displacement experiments in both tissues demonstrated that the lipid solubility of a particulr mAchR ligand might play an important role in determining its profile of binding to the mAchR, and the concentrations of mAchR in rat brain are both on the cell surface (membrane-bound receptor) and in the intracelluar membrane (intermembrane-bound receptor). 4. The results are discussed in terms of the usefulness of dissociated intact rat brain cells in studying mAchR in central nervous system.

• Korean Journal of Veterinary Research
• /
• v.28 no.1
• /
• pp.17-22
• /
• 1988

평골근(平滑筋)으로 된 자궁근(子宮筋)은 자동성(自動性)을 가지고 있어서 신경지배(神徑支配)와 관계(關係)없이 근자체(筋自體)로 운동(運動)을 하게 된다. 그러나 이러한 자궁근(子宮筋)의 형태적(形態的) 및 기능적(機能的) 정상상태유지(正常狀態維持)에는 estrogen의 작용(作用)이 불가결(不可缺)한 요소(要素)로 되어 있으며 이 estrogen의 작용(作用)에 의하여 histamine의 자궁근(子宮筋)에 대한 (작용)作用이 수용체(受容體)의 어떤 기전에 의한 것인지를 알기 위하여 본(本) 연구(硏究)는 histamine과 5-hydroxytryptamine 및 이들 길항물질(拮抗物質)들의 자궁근(子宮筋) 운동성(運動性)에 대한 수축(收縮) 및 이완작용(弛緩作用)을 조사(調査)하였다. 자궁근(子宮筋)의 운동성(運動性)은 physiograph를 통(通)해 자궁수축(子宮收縮)의 빈도(頻度)와 크기를 기록하여 아래와 같은 결론(結論)을 얻었다. 1. 5-hydroxytryptamine에 대한 phenoxybenzamine의 억제작용(抑制作用)은 phenoxybenzamine의 길항성(拮抗性)의 결과(結果)이다. 2. histamine은 $H_1$-receptor를 통해서 흰쥐의 자궁평활근(子宮平滑筋)의 운동성(運動性)은 증가(增加)한다. 3. 반면 histamine은 $H_2$-receptor를 통해서는 자궁평활근(子宮平滑筋)의 운동성(運動性)을 이완(弛緩)시켰다. 4. 흰쥐의 자궁근(子官筋)에서 $H_2$-receptor 차단제(遮斷劑)가 $H_1$-receptor 차단제(遮斷劑)의 작용(作用)보다 더욱 강하였다.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.46 no.1
• /
• pp.43-47
• /
• 2020

A novel series of adamantyl derivatives of N-aryl amides as androgen receptor antagonists were synthesized and their anti-androgenic activities were evaluated. The N-aryl amides containing adamantyl derivatives had more activity than those lacking adamantyl substitutions. The synergistic effect of bulkiness of the adamantyl group and modulation of electron density on the aromatic ring by pendant groups was crucial to the potent antagonism. Molecular modeling studies were performed to elucidate the interactions between ligands and receptors.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.04a
• /
• pp.284-284
• /
• 1994

Pentazocine은 opioid 수용체에 대한 흥분작용과 길항작용을 겸유한 opioid계 약물로 알려져 있다. 본 연구에서 흰쥐 적출 관류부신 으로 부터 pentazocine의 catecholamine (CA) 분비작용을 관찰하여 그 기전을 규명하고 또한 다른 opioid의 작용과 비교하여 얻어진 결과는 다음과 같다. Pentazocine (30-300$\mu\textrm{g}$)을 부신정맥내에 주사하였을때 현저한 용량 의존성의 CA 분비 작용을 나타내었다. Pentazocine의 이러한 CA 분비작용은 chlorisondamine ($10^{-6}$M), naloxone (1.22 $\times$ $10^{-7}$M), morphine (1.73 $\times$ $10^{-5}$M). enkephalin (9.68 $\times$$10^{-6}$M), nicardipine ($10^{-6}$M) 및 TMB-8 ($10^{-5}$M)등의 전처치로 뚜렷이 억제되었으나 pirenzepine (2 $\times$ $10^{-6}$M)의 전처치에 의해서는 영향을 받지 않았다. $Ca^{++}$-free Krebs 용액으로 30분간 관류한 후에 pentazocine의 CA 분비작용은 현저한 감소를 나타내었다. Pentazocine (1.75 $\times$ $10^{-4}$M)을 20분간 관류시킨 후에 ACh (5.32 $\times$ $10^{-3}$M)과 DMPP ($10^{-4}$M)에 의한 CA 분비작용이 의의있게 감약되었다.

• Korean journal of applied entomology
• /
• v.61 no.1
• /
• pp.101-108
• /
• 2022

Because of their specificity to target insects and relatively low toxicity to non-target organisms, insect growth regulators (IGRs) have been regarded as attractive alternatives to chemical insecticides. Commercially available IGRs are classified into juvenile hormone agonists (JHAs), ecdysone agonists (EAs), and chitin synthesis inhibitors (CSIs) according to their mode of action. Recently, JH-mediated interaction of methoprene-tolerant (Met), which is JH receptor, and its binding partners have been replicated in vitro using yeast cells transformed with the Met and FISC/CYC genes of A. aegypti. Using this in vitro yeast two-hybrid β-galactosidase assay, juvenile hormone antagonists (JHANs) have been identified from various sources including chemical libraries, plants, and microorganisms. As juvenile hormone (JH) is an insect specific hormone and regulates development, reproduction, diapause and other physiological processes, JHANs fatally disrupt the endocrine signals, which result in abnormal development and larval death. These results suggested that JHANs could be efficiently applied as IGR insecticides with a broad insecticidal spectrum. This review discuses JH signaling pathway mediated by Met and future prospects of JHANs as environmentally benign IGR insecticides.

• Korean Journal of Weed Science
• /
• v.12 no.1
• /
• pp.39-45
• /
• 1992

This experiment was conducted to evaluate the effect of gibberellin biosynthesis retardants as used by rice lodging inhibitors on the gibberellin antagonism, auxin interation, ethylene evolution and growth of second crops. Results obtained can be summarized as follows. Inabenfide, paclobutrazol and uniconazole markedly inhibited the epicotyl elongation of mung bean. Inhibiting effect of epicotyl by these chemicals was markedly stimulated by gibberellic acid, thus showing clear antagonism between these chemicals and gibberellic acid. Significantly large number of roots were formed in the mung bean cuttings which were rooted in the paclobutrazol and uniconazol of 1 ppm. The higher the concentration, the more the number of roots forms. It was guessed that these effect was closely related with auxin. Ethylene evolution was a little stimulated in the leaf of rice under the treatment of inabenfide, paclobutrazol and uniconazole at earlier stage(5 DAT), however it was suppressed at later stage(10, 30 DAT) at higher concentration. The effect of gibberllin biosynthesis inhibitors to second crops retarded tomato plants without influencing the height of barley. The treatment of paclobutrazol and uniconazol which is triazole-type more severely inhibited than that of inabenfide which is isonicotinanilide-type. The more the concentration, the less the height of tomato plants.

• The Korean Journal of Pharmacology
• /
• v.30 no.1
• /
• pp.101-109
• /
• 1994

Pharmacological characterization of GS 283, a tetrahydroisoquinoline derivative has been elucidated using rat thoracic aorta, guinea pig tenea coli and rabbit mesentery artery in vitro. GS 283 showed calcium antagonistic action in vascular smooth muscle, since high $K^+-induced$ contraction was concentration dependently inhibited. GS 283 also inhibited the contraction induced by ${\alpha}_1$ receptor activation. Vasodilating action of GS 283 was not modified by the propranolol, indicating that GS 283 has no ${\beta}$ receptor stimulatory action. Simultaneous measurement of intracellular calcium change and muscle tension indicated that the inhibitory effect of GS 283 was accompanied by the increase in tissue fluorescence. This increment was not due to fura 2 fluorescence but to endogenous pyridine nucleotide, suggesting that GS 283 has an effect to inhibit mitochondrial function. GS 283 had an inhibitory action on cyclic AMP and GMP-dependent phosphodiesterases from rat brain with Ki values of 2.5 and 6.7 mM. From these findings we concluded that GS 283 has multiple action such as the inhibition of cyclic nucleotide-dependent phosphodiesterases, blocking of calcium channel as well as inhibition of mitochondrial function which are responsible for vasodilatation.

• Korean Journal of Organic Agriculture
• /
• v.7 no.1
• /
• pp.137-146
• /
• 1998

Various rhizobacteria was isolated, and was bacterialized into the substrates to clarify the plant growth promoting effects of rhizobacteria on the early growth of red peper seedlings. Total 125 bacterial isolates were primarily isolated and purified from the soils in greenhouse. And four strains were finally screened, based on the antifungal activities against Fusarium sp., Pythium sp. and Rhizoctonia sp. of red pepper plants. The strongest antifungal strain RB 109 has a antagonistic activity against Fusarium sp., Pythium sp. and Rhizoctonia sp. in terms of 66.0%, 65.0% and 66.1%. Early growth of red pepper seedlings was promoted, when cultured solution of rhizobacteria RB 109 was bacterialized into the substrates. Antifungal rhizobacteria RB 109 was identified as Pseudomonas sp. related strains, which has a similarity of 82% to the Pseudomonas sp.