• Title/Summary/Keyword: 카테콜

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Influence of Hypoxia on Catecholamine Secretion Evoked by DMPP, McN-A-343, Excess $K^+$ and ACh from The Perfused Rat Adrenal Gland (저산소증이 흰쥐 관류부신에서 DMPP, McN-A-343, Excess $K^+$ 및 Ach의 카테콜아민 분비작용에 미치는 영향)

  • Lim Dong-Yoon;Heo Jae-Bong;Park Yoo Han
    • The Korean Journal of Pharmacology
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    • v.31 no.1 s.57
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    • pp.63-74
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    • 1995
  • It has been known that, during hypoxia, the adrenal medulla is activated to release catecholamines (CA) while hypoxia also inhibits high $K^+$ -induced CA secretion in the cultured bovine adrenal chromaffin cells. The present study was attempted to examine the effect of hypoxia on CA secretion evoked by chlinergic stimulation and membrane-depolarization from the isolated perfused rat adrenal glands and also to clarify its mechanism of action. For this purpose, using the isolated rat adrenal glands, the effects of hypoxia on CA release evoked by nicotinic ($N_1$) and muscarinic ($M_1$) receptor agonists, membrane-depolarizing agent, $Ca^{++}$-channel activator, intracellular $Ca^{++}$-releaser and ACh were determined. Experiments were carried out, perfusing Krebs solution pre-equilibrated with a gas mixture of 95% N_2$ and 5% $CO_2$. Hypoxia was maintained for $3{\sim}4$ hours through the experiments. Hypoxia gradually caused a time-dependent seduction in CA secretion evoked by DMPP ($100{\mu}M$), McN-A-343 ($100{\mu}M$), ACh (5.32 mM), Bay-K-8644 ($10{\mu}M$) and high $K^+$ (56 mM) respectively. How-ever, it did not affect CA secretion evoked by cyclopiazonic acid ($10{\mu}M$). Hypoxia itself also did fail to produce any influence on spontaneous secretory response of CA. These experimental results suggest that hypoxia depresses CA release evoked by both cholinergic stimulation and membrane-depolarization from the isolated rat adrenal medulla, and that this inhibitory activity may be due to the result of the direct inhibition of $Ca^{++}$ influx into the chromaffin cells without any effect on the calcium mobilization from the intracellular store.

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Recovery Trajectory in Tachycardia Induced Heart Failure Model (빈맥을 이용한 심부전 모델에서 회복궤도)

  • 오중환;박승일;원준호;김은기;이종국
    • Journal of Chest Surgery
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    • v.32 no.5
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    • pp.422-427
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    • 1999
  • Background: Tachycardia induced heart failure model would be the model of choice for the dilated cardiomyopathy. This more closely resembles the clinical syndrome and does not require major surgical trauma, myocardial ischemia and pharmacological or toxic depression of cardiac function. When heart failure is progressive, application of new surgical procedures to the faling heart is highly risky. It has been shown that recovery trajectory from heart failure is a new method in decreasing animal mortality. The purpose is to establish the control datas for recovery trajectory in the canine heart failure model. Material and Method: 21 mongrel dogs were studied at 4 stages(baseline, at the heart failure, 4 and 8 weeks after recovery). Heart failure was induced during 4 weeks of continuous rapid pacing using a pacemaker. Eight weeks of trajectory of recovery period was allowed. Indices of left ventricular function and dimension were measured every 2 weeks and the hemodynamics were measured by use of Swan-Ganz catheterization and thermodilution method every 4 weeks. Values were expressed as mean${\pm}$standard deviation. Result: 4(20%) dogs died due to heart failure. Left ventricular end-diastolic volume at the 4 stages were 40.8${\pm}$7.4, 82.1${\pm}$21.1, 59.9${\pm}$7.7 and 46.5${\pm}$6.5ml. Left ventricular end-systolic volume showed the same trend. Ejection fractions were 50.6${\pm}$4.1, 17.5${\pm}$5.8, 36.3${\pm}$7.3, and 41.5${\pm}$2.4%. Blood pressure and heart rate showed no significant changes. Pressures of central vein, right ventricle, pulmonary artery, and pulmonary capillary wedge showed significant increase during the heart failure period, normalizing at the end of recovery period. Stroke volumes were 21.5${\pm}$8.2, 12.3${\pm}$3.5, 17.9${\pm}$4.6, and 15.5${\pm}$3.4ml. Blood norepinephrine level was 133.3${\pm}$60.0pg/dL at the baseline and 479.4${\pm}$327.3pg/dL at the heart failure stage(p=0.008). Conclusion: Development of tachycardia induced heart failure model is of high priority due to ready availability and reasonable amenability to measurements. Recovery trajectory after cessation of tachycardia showed reduction of cardiac dilatation and heart function. Application of new surgical procedures during the recovery period could decrease animal mortality.

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Interrelationship between Dopaminergic Receptors and Catecholamine Secretion from the Rat Adrenal Gland (흰쥐 부신에서 카테콜아민 분비작용과 도파민 수용체간의 상관성)

  • Lim, Dong-Yoon;Yoon, Joong-Keun;Moon, Baek
    • The Korean Journal of Pharmacology
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    • v.30 no.1
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    • pp.87-100
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    • 1994
  • It has been known for some time that dopamine-containing cells are existed in sympathetic ganglia, i.e., small, intensely fluorescent cells. However, its role and mechanism of action as a peripheral neurotransmitter are poorly understood so far. In the present study, an attempt was made to examine the effect of apomorphine, which is known to be a selective agonist of dopaminergic $D_2$. receptor on secretion of catecholamines (CA) from the isolated perfused rat adrenal gland. The perfusion of a low concentration of 10uM apomorphine into an adrenal vein for 20 min produced significant reduction in CA secretion induced by 5.32 mM ACh, 56 mM KCl, 100 uM DMPP and 100 uM McN-A-343. Increasing apomorphine concentration to 30 uM led to more markedly decreased CA secretion as compared to the case of 10 uM apomorphine and also did inhibit clearly CA release by $10^{-5}M$ Bay-K-8644. Furthermore, in adrenal glands preloaded with a higher dose of 100 uM apomorphine, CA releases evoked by ACh, excess $K^+$, DMPP and McN-A-343 were almost abolished by the drug. The perfusion of $3.3{\pm}10^{-5}M$ metoclopramide, which is well-known as a selective dopaminergic $D_2$ antagonist, produced significantly inhibitory effect of CA release by ACh, DMPP and McN-A-343 but did not affect that by excess $K^+$. However, preloading of 30uM apomorphine in the presence of metoclopramide did not modify the CA secretory effect of excess $K+$ and DMPP. These experimental results demonstrate that apomorphine causes dose-dependent inhibition of CA secretion by cholinergic receptor stimulation and also by membrane depolarization from the isolated perfused rat adrenal gland, suggesting that these effects appear to be exerted by inhibiting influx of extracellular calcium into the rat adrenal medullary chromaffin cells through activation of inhibitory dopaminergic receptors.

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Effect of 6-Hydroxydopamine (6-OHDA) on the Expression of Hypothalamus-Pituitary Axis Hormone Genes in Male Rats (수컷 흰쥐의 시상하부-뇌하수체 축 호르몬 유전자 발현에 미치는 6-Hydroxydopamine(6-OHDA)의 영향)

  • Heo, Hyun-Jin;Ahn, Ryun-Sup;Lee, Sung-Ho
    • Development and Reproduction
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    • v.13 no.4
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    • pp.257-264
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    • 2009
  • A neurotoxin, 6-hydroxydopamine (6-OHDA) has been widely used to create animal model for Parkinson's disease (PD) due to its specific toxicity against dopaminergic (DA) neurons. Since DA signals modulate a broad spectrum of CNS physiology, one can expect profound alterations in neuroendocrine activities of both PD patients and 6-OHDA treated animals. Limited applications of 6-OHDA injection model, however, have been made on the studies of hypothalamuspituitary neuroendocrine circuits. The present study was performed to examine whether blockade of brain catecholamine (CA) biosynthesis with 6-OHDA can make any alteration in the transcriptional activities of hypothalamus-pituitary hormone genes in adult male rats. Three-month-old male rats (SD strain) were received 6-OHDA ($200{\mu}g$ in $10{\mu}\ell$ of saline/animal) by intracerebroventricular (icv) injection, and sacrificed after two weeks. To determine the mRNA levels of hypothalamuspituitary hormone genes, total RNAs were extracted and applied to the semi-quantitative RT-PCRs. The mRNA levels of tyrosine hydroxylase (TH), the rate-limiting enzyme for the catecholamine biosynthesis, were significantly lower than those from the control group (control:6-OHDA=1:0.72${\pm}$0.02AU, p<0.001), confirming the efficacy of 6-OHDA injection. The mRNA levels of gonadotropin-releasing hormone (GnRH) and corticotropin releasing hormone (CRH) in the hypothalami from 6-OHDA group were significantly lower than those from the control group (GnRH, control:6-OHDA=1:0.39${\pm}$0.03AU, p<0.001; CRH, control:6-OHDA=1:0.76${\pm}$0.07AU, p<0.01). There were significant decreases in the mRNA levels of common alpha subunit of glycoprotein homones (Cg$\alpha$), LH beta subunit (LH-$\beta$), and FSH beta subunit (FSH-$\beta$) in pituitaries from 6-OHDA group compared to control values (Cg$\alpha$, control:6-OHDA=1:0.81${\pm}$0.02AU, p<0.001; LH-$\beta$, control:6-OHDA=1:0.68${\pm}$0.04AU, p<0.001; FSH-$\beta$, control:6-OHDA=1:0.84${\pm}$0.05AU, p<0.001). Similarly, the level of adrenocorticotrophic hormone (ACTH) transcripts from 6-OHDA group was significantly lower than that from the control group (control: 6-OHDA=1:0.86${\pm}$0.04AU, p<0.01). The present study demonstrated that centrally injected DA neurotoxin could downregulate the transcriptional activities of the two hypothalamus-pituitary neuroendocrine circuits, i.e., GnRH-gonadotropins and CRH-ACTH systems. These results suggested that hypothalamic CA input might affect on the activities of gonad and adrenal through modulation of hypothalamus-pituitary function, providing plausible explanation for frequent occurrence of sexual dysfunction and poor stress-response in PD patients.

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Influences of Gastric Mucosa upon the Catecholamine Induced Gastric Motility in Guinea-pig (기니피그 위점막이 카테콜아민 유발 위운동에 미치는 영향)

  • Rhee, Poong-Lyul;Kim, Ki-Whan;Lee, Sang-Jin
    • The Korean Journal of Physiology
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    • v.23 no.2
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    • pp.277-289
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    • 1989
  • The effects of noradrenaline on the contractile and electrical activities were investigated using the circular muscle strips with intact mucosa prepared from the antrum and fundus of guinea-pig stomach. Electrical responses of circular muscle cells were recorded using glass capillary microelectrodes filled with 3 M KCI. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2\;and\;kept\;at\;35^{\circ}C$. The results obtained were as follows: 1) The spontaneous contractions recorded from the antral and fundic circular muscle strips with intact mucosa were suppressed dose-dependently by the application of noradrenaline, whereas those recorded from the mucosa-free strips were potentiated in a dose-dependent manner. 2) The inhibitory influences on the contractile activities in the normal intact strips were developed via both ${\alpha}-adrenoceptors\;and\;{\beta}-adrenoceptors$, while the excitatory influences in the mucosa-free strips resulted from the strong excitatory effect via ${\alpha}-adrenoceptors$ and the weak inhibitory effect via ${\beta}-adrenoceptors$. 3) Noradrenaline produced hyperpolarization of membrane potential, and increased the amplitude and the maximum rate of rise of slow waves in the mucosa-free strips of antral and fundic circular muscle. 4) Apamin blocked the appearance of the component of initial suppression of spontaneous phasic contractions observed in the mucosa-free strips of antral circular muscle after the application of noradrenaline. 5) The inhibitory influences on the contractile activities in the normal strips with intact mucosa remained unaffected even in the strip with separate mucosa, in which mucosa and muscle layer were mechanically disconnected . From the above results, following conclusions could be made. (1) There are no regional differences between the effects of noradrenaline on the antral circular muscle and those on the fundic circular muscle. (2) Excitatory responses to noradrenaline observed in the mucosa-free strip result from the dominant ${\alpha}-excitatory$ and tile weak ${\beta}-inhibitory$ action of noradrenaline. (3) Inhibitory responses to noradrenaline in the normal strips with intact mucosa develop via both ${\alpha}-inhibitory\;and\;{\beta}-inhibitory$ actions.

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Streets of Relaxation Therapy and Exercise Therapy on Catecholamine and Heart Rate Response for Job Stress of White Color Workers (사무직 근로자에 대한 운동요법과 이완요법이 스트레스 반응으로 카테콜라민과 심박수에 미치는 영향)

  • Kim In-Hong
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.6 no.2
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    • pp.240-254
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    • 1999
  • The purpose of this study was to investigate the effect of exercise therapy and relaxation therapy on catecholamine and heart rate in people in white color jobs and to determine this information the effectiveness of applied exercise therapy and relaxation therapy as a nursing intervention method for stress patients. The subjects were divided into an exercise therapy group, a relaxation therapy group, and control group and the research design was a nonequivalent control group pretest-post test design(exercise therapy : n= 12, relaxation therapy : n=12, control group, the group without any treatment in exercise on relaxation therapy : n=12), The subjects in the exercise therapy group were given a particular intensity for each kp during 30min, bicycle ergometer which is using an LX PE training system before & after 4weeks of training. The exercise therapy that was used was Astrard load method which tested absolute exercise load of heart rate before & after four weeks, and resting heart rate was tested for exercise and relaxation therapy before, after four weeks, and at eight weeks. The results of each kp & absolute exercise load were calculated with the target rate formula(maximal heart rate-rest heart rate) x exercise intensity(%) + rest heart rate so the subjects could continue 60-70% exercise intensity for exercise therapy over eight weeks. The relaxation therapy subjects were trained using a modified Jacobson's relaxation technique for eight weeks. The exercise and relaxation therapy were trained at the following intensity for eight weeks(3times/week, 30min/day) to see changes in catecholamine & heart rates. After eight weeks, statistical analysis of exercise & relaxation therapy were carried out Two-way ANOVA and multiple range test(SNK : Student Newman Keul) were used. The results are as follows : 1. The change of epinephrine & norepinephrine in the exercise therapy, relaxation therapy, and control group was statistically significant at the .05 level after four weeks & eight weeks. Also, exercise therapy was statistically significant at .05 level over that of the control group after 4weeks. 2. The change of heart rate in relaxation therapy was statistically significant at the .05 level, and was statistically significant at the .05 level over that of the exercise therapy and control group. In conclusion, it is obvious that exercise therapy and relaxation therapy should be one of the most effective stress treatment and desirable nursing interventions methods for job stress in people in white color jobs.

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CHILDHOOD TRAUMA:PSYCHIATRIC OVERVIEW (아동기 외상의 정신과적 개관)

  • Han, Sung-Hee
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.13 no.1
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    • pp.3-14
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    • 2002
  • Childhood psychic trauma appears to be a crucial factor in the development of serious disorders both in childhood and in adulthood. Traumatized children show strong tendency to revisualize or re-feel a traumatic events. Play and behavioral reenactments are frequent manifestations of both the single blow and the long-standing traumas in childhood. Those children who suffer the results of single, intense terror appear to exhibit detailed memory, retrospective reworkings and misperceptions. In long-standing or repetitive trauma, children would show psychic numbing, self-hypnosis, dissociation and rage. Child's brain is undergoing critical and sensitive periods of differentiation. During this time, developing central nervous system is exquisitely sensitive to stress. Stressor-activated neurotransmitters and hormones can play major roles in neurogenesis, migration, synaptogenesis, and neurochemical differentiation. Internal opiate system operates in some trauma and causes the victim to fail to respond, to avoid, to shut off feelings. Evidence is also accumulating in traumatology that dysfuntion of locus coeruleus and ventral tegmental neucleus system leads to catecholamine receptors hypersensitivity. This change result in hypervigilance, increased startle, affective lability, and increased autonomic nervous system hyperreactivity. Another site of action of trauma on the brain is hypothalamic-pituitary-adrenal axis. Individuals with PTSD do not have enough cortisol to halt the alarm reaction. When children are exposed to long-standing extreme events, massive attempts to protect the psyche and to preserve the self are put into gear. These developmental traumas mobilize various kinds of defense mechanisms. Massive denial, dissociation, self anesthesia, identification with aggressor and aggression turned against the self often lead to profound character changes in the youngsters.

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Contribution of Different Types of $Ca^{2+}$ channels to Catecholamine Secretion in Rat Adrenal Chromaffin Cells (부신수질 Chromaffin 세포의 $Ca^{2+}$ 통로유형이 카테콜아민 분비에 미치는 영향에 관한 정량적 연구)

  • Goo, Yang-Soak;Roh, Jin-A;Lee, Jung-Hwa;Chao, Eun-Jong
    • Progress in Medical Physics
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    • v.8 no.1
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    • pp.3-15
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    • 1997
  • Adrenal chromaffin cells secrete catecholamine in response to acetylcholine. The secretory response has absolute requirement for extracellular calcium, indication that $Ca^{2+}$ influx through voltage dependent $Ca^{2+}$ channel (VDCC) is the primary trigger of the secretion cascade. Although the existence of various types of $Ca^{2+}$ channels has been explored using patch clamp technique in adrenal chromaffin cells, the contribution of different types of $Ca^{2+}$ channels to catecholamine secretion remains to be established. To investigate the quantative contribution of different types of $Ca^{2+}$ channels to cate-cholamine secretion, $Ca^{2+}$ current($I_{Ca}$) and the resultant membrane capacitance increment($\Delta{C}_{m}$) were simultaneoulsy measured. Software based phasor detector technique was used to monitor $\Delta{C}_{m}$. After blockade of L type VDCC with nicardipine (1$\mu$M), $I_{ca}$ was blocked to 43.85$\pm$6.72%(mean$\pm$SEM) of control and the resultant ㅿC$_{m}$ was reduced ot 30.10$\pm$16.44% of control. In the presence of nicardipine and $\omega$-conotoxin in GVIA(l$\mu$M), an N type VDCC antagonist, $I_{ca}$ was blocked to 11.62$\pm$2.96% of control and the resultant $\Delta{C}_{m}$ was reduced to 26.13$\pm$8.25% of control. Finally, in the presence of L, N, and P type $Ca^{2\pm}$ channel antagonists(nicardipine, $\omega$-Conotoxin GVIA, and $\omega$-agatoxin IVA, respectively), $I_{ca}$ and resultant $\Delta{C}_{m}$ were almost completely blocked. From the observation of parallel effects of $Ca^{2+}$ channel antagonists on $I_{ca}$ and $\Delta{C}_{m}$, it was concluded that L, N, and also P type $Ca^{2+}$ channels served and $Ca^{2+}$ source for exocytosis and no difference was observed in their efficiency to evoke exocytosis amost L, N, and P type $Ca^{2+}$ channels.

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Neural Circuits Mediating Stress (스트레스의 신경생물학적 이해)

  • Yu, Bum-Hee;Woo, Jong-Min
    • Korean Journal of Psychosomatic Medicine
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    • v.9 no.1
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    • pp.81-92
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    • 2001
  • Stress has been linked to the pathophysiology and pathogenesis of various psychiatric illnesses. Over the past few years, our understanding of the brain and neuroendocrine systems that are linked to stress responses has increased enormously. This article reviews a series of animal and human studies to understand what are the central pathways by which stress is perceived, processed, and transduced into a neuroendocrine response. We focus on the limbic-hypothalamic-pituitary-adrenal(LHPA) axis and several neurotransmitter systems such as norepinephrine, CRF, serotonin, acetylcholine, and dopamine. LHPA stress circuit is a complex system with multiple control mechanisms which are altered in pathological states. CRF and related peptides in the central nervous system appear to enhance behavioral responses to stressors. Norepinephrine systems are also activated by stressors and cause the release of catecholamines from the autonomic nervous system. CRF-norepinephrine interaction makes a feed-forward system which may be important for an organism to mobilize not only the pituitary system but also the central nervous system, in response to environmental challenges. The interactions among several neurotransmitters and endocrine systems appear to play key roles in mediating various behavioral and psychological stress responses involving abnormal responses to stressors such as anxiety and affective disorders.

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Effect of 2-hydroxypropyl-$\beta$-cyclodextrin on Biodegradation of High-Molecular Weight Polycyclic Aromatic Hydrocarbons by Novosphingobium pentaromtivorans US6-1 (Novosphingobium pentaromtivorans US6-1에 의한 고분자 방향족 탄화수소 생분해과정에서 2-hydroxypropyl-$\beta$-cyclodextrin의 영향)

  • Kang Ji-Hyun;Kwon Kae Kyoung;Kim Sang-Jin
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.7 no.3
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    • pp.146-151
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    • 2004
  • Cyclodextrin compounds including 2-hydroxypropyl-β-cyclodextrin(β-HPCD) though to be accelerate the biodegradation of PAHs molecule by increasing solubility of PAHs through detaining PAHs in their's cavity. However, only this mechanism is not sufficient to explain the enhancement of PAHs biodegradation by β-HPCD. To find out possible additional role of β-HPCD in the enhancement of PAHs biodegradation, biodegradation rates of pyrene and benzo[a]pyrene (B[a]P) by a PAHs degrading Novosphingobium pentaromtivorans US6-1 strain were compared between with and without addition of β-HPCD. Changes of bacterial biomass were also measured simultaneously. In addition catechol 1,2-dioxygenase activity was determined depending on pre-incubation conditions. As a result, β-HPCD accelerate the degradation rate of pyrene by strain US6-1 and especially the β-HPCD amendment was obligatory for the degradation of B[a]p. Bacterial biomass was responsible for β-HPCD, however, PAHs compounds such as pyrene and B[a]P did not contribute to the bacterial biomass. Catechol 1,2-dioxygenase specific activity of US6-l cells pre-cultured in MM2 medium containing l% β-HPCD was higher than that of cells pre-cultured in ZoBell medium. The former case also showed similar activity compared to that of cells serially starved in MM2 medium after grown in ZoBell medium. These results imply that the presence of β-HPCD accelerate the degradation of PAHs by increasing the bacterial biomass as well as by increasing the water solubility of PAHs.

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