Effects of Iron Chelators and Reducing Agents on Iron induced Lipid Peroxidation

Park, Chan-Hyun,Lee, Chung-Soo,Shin, Yong-Kyu,Lee, Kwnag-Soo 중앙대학교 의과대학 의과학연구소 1987 中央醫大誌 Vol.12 No.3

금속이온 가운데 iron은 산소라디칼에 의한 생체 세포내 거대분자의 파괴를 촉매하며 iron의 환원이 지질의 과산화에 주요한 역할을 하는 것으로 알려져 있다. OH·을 생성하는 Haber-Weiss reaction은 iron에 의하여 촉진되며, 생성된 OH·이 지질의 과산화를 초래하는 물질로서 시사되고 있다. Iron에 의한 불포화 지방산의 과산화에는 ferrous-dioxygen복합체 또는 제일 철(혹은 착화 제일 철)의 자가산화 반응중에 산소라디칼이 형성되어 이들이 관여하는것으로 추측하고 있다. 한편 다수의 보고들은 생체내에 존재하는 환원제의 하나로써 ascorbate가 지질의 과산화를 포함한 세포내 거대분자의 손상을 초래하며 또한 금속이온의 독성작용을 항진시킨다고 보고하고 있다. 이와 같이 iron의 산화와 환원이 지질의 과산화에 관여할 가능성에서 볼 때, ascor-bate와 같은 환원제들의 환원력이 갖는 역할은 이들의 독성작용에 기여하는 작용을 밝히는 계기가 될 것이다. 그러므로 본 연구에서는 iron의 산화 또는 환원에 따른 조직 손상의 정도를 여러 환원제와 iron chelator존재하에서 나타나는 현상으로써 측정하였다. 이들 효과는 iron의 산화중에 유리되는 산소라디칼과 microsome의 지질의 과산화를 통하여 관찰하였다. 또한 이온의 산화 및 환원에 미치는 iron chelator와 환원제들의 영향을 관찰하였으며 더 나아가 iron의 산화 및 환원과 이에 따른 지질의 과산화 사이의 관계를 규명하였다. Fe^++은 microsome의 질을 과산화시켰으나 Fe^++은 100uM농도까지 지질의 과산화에 약간의 영향을 나타내었다. 중성의 반응액에서 Fe^++ 은 5분내에 거의 완전히 산화되었으며 이와 동시에 ferricytochrom c가 환원되었다. 이에 반하여 Fe^++은 ferricytochrom c의 환원에 거의 영향을 나타내지 아니 하였다. Fe^++에 의한 microsome지질의 과산화는 O_2의 scavenger인 SOD와 H_2o_2의 scavenger인 catalase 에 의하여 억제되었다. EDTA 또는 DETAPAC은 Fe^++에 의한 microsome 지질의 과산화에 이중효과를 나타내었으며 EDTA 또는 DETAPAC과 iron의 결합이 1:2일때 iron에 의한 지질의 과산화는 증가하였으나, 이러한 비율에서 벗어날 때는 오히려 iron에 의한 지질의 과산화는 억제되었다. ADP 는 Fe^++에 의한 지질의 과산화를 억제하였으나 Fe^++에 의한 지질의 과산화를 촉진시켰다. EDTA또는 ADP 는 Fe^++의 자발적인 산화를 촉진하였으나 DETAPAC은 용량에 따라 억제하였다. 한편 salicylate의 hydroxylation은 EDTA나 DETAPAC 에 대한 Fe^++의 결합비율이 2:1일 때 가장 크게 이루어졌으며 이러한 비율에서 벗어날때 hydroxylation속도는 감소되었다. ADP 또한 salicylate 의 hydroxylation 을 억제하였다. 여러 환원제 가운데 ascorbate는 Fe^+++의 환원과 iron에 의한 지질의 과산화를 가장 강력하게 촉진하였다. Fe^++와 ascorbate의 첨가에 따른 지질의 과산화는 Fe^+++와 ascorbate에 의한 것보다 훨씬 현저하였다. Fe^++또는 Fe^++와 ascorbate 의 상호반응에 의한 ferricytochrom c의 환원은 SOD에 의하여 뚜렷하게 억제되었으나, ascorbate 자체에 의한 ferricytochrom c의 환원은 SOD에 의하여 약간 억제되었다. 한편 cysteine,NADH와 giutathione중에서 cysteine에 의한 ferricytochrom c 의 환원만이 SOD 에 의하여 억제되었다. 이상의 결과로부터 iron의 산화와 환원을 억제 또는 촉진시키는 물질은 지질의 과산화를 억제하거나 촉진 시키므로 iron의 산화 및 환원과 지질의 과산화 사이에는 관계가 있을 것으로 사료되었다. 또한 이러한 반응에서 OH·같은 산소라디칼이 iron의 산화 및 환원에 따른 지질의 과산화를 초래하는 매개물질로서 작용할 가능성이 시사되었다. Iron is a reactive metal ion which is known to catalyze damages of cellular rnacrornolecules causrd by oxygen radicals and its reduction may play a major role in lipid peroxidation. The iron-catalyzed Hater-Weiss reaction to produce OH is catalyzed by iron and OH appear to participate as an initiator of lipid peroxidation. Ferrous(or chelated) ion will also initiate peroxidation of unsaturated fatty acids. This initiation may of cur via abstraction by a ferrous-dioxygen complex or alternatively may involve 0_2, H_2O_2 or other partially reduced oxygen species generated through fur-ther autoxidation reactions of the ferrous che-lates. Many studies have reported toxic effects of ascorbate on various biological materials including lipid and DNA peroxidation. In view of data suggesting that the effect of iron on lipid peroxidation is mediated by its oxidore-duction, reducing actiyity of reducing agents such as ascorbate may be the mechanism through which the toxic action of ascorbate is mediated. In the Present study, the effect of oxidore-ducticn of iron on tissue damages was inves-tigated in the presence of various reducing agents or iron chelators. These effects were studied with respect to generation of oxygen radicals during oxidation or reduction of iron in relation to the lipid peroxidation caused by iron. The effects of reducing agents or iron chelators on redox phenomenon of iron were also observed. Furthermore, the relationship between oxidoreduction of iron and lipid pero-xidation was studied. Lipid peroxidation of microsomes was increased with concentration of Fe^++, but Fe^+++ had little effect. In reaction medium of pH 7.4, Fe^++ was almost compte-tely autoxidized at 5 min after the reaction and during this process superoxide radical was formed. Lipid peroxidation of microsomes by Fe^++ was inhibited by SOD and catalase. EDTA or DETAPAC showed dual effects on lipid peroxidation by Fe^++ When proportion of these chelators to iron was 1:2, lipid peroxidation was enhanced but when this ratio is altered, lipid peroxidation was inhibited. ADP prevented lipid peroxidation by Fe^++ and stimulated that by Fe^+++, EDTA or ADP facilitated autoxidation of Fe^++ whereas DE-TAPAC inhibited. On the other hand, when proportion of EDTA or DEfAPAC to Fe^++ was 1:2, hydroxylation of sodium salicylate was maximum and fell off as this proportion was altered. ADP also prevented hydroxylation of salicylate by Fe^++ Among various reducing agents tested ascorbate had a most potent reducing power and also most remarkably facilitated lipid peroxidation by iron. Lipid peroxidation caused by interaction of Fe^++ and ascorbate was greater than that by interaction of Fe^++ plus ascorbate. Reduction of ferricyto-chrorne c was enhanced by ascorbate in a dose dependent manner, but other reducing agents showed little effect. Reduction of ferricytoch-rorne c by Fe^++ alone or Fe^++ plus ascorbate was signifi cantly inhibited by SOD. However, reduction of ferricytochrorne c by ascorbate alone was slightly inhibited by SOD. From these results obtained, it is suggested that oxidoreduction of iron plays the major role in tissue damages including lipid peroxidation caused by iron dependent reactions and there is the relationship between the oxidoreduction of iron and lipid peroxidation. Also, it appears that oxygen radicals such as OH·plays at least a partial role in initiating lipid peroxidation.

성장기 학생들에 있어서 카드뮴과 아연의 혈중 농도

박정덕,최병선,홍연표,장임원 중앙대학교 의과대학 의과학연구소 1996 中央醫大誌 Vol.21 No.2

We analyzed the level of blood cadmium for 245 growing students(135 males and 110 females) aged 6 to 24 years who had not exposed to cadmium as the exposure index for cadmium in general population, and studied the reference value, sex- and age- effect for the blood cadmium, in addition relation with blood zinc. Blood cadmium and zinc determined using atomic absorption spectrophotometry by flameless method for cadmium and flame method for zinc. The mean value of blood cadmium was 0.92㎍/ℓ in arithmetic mean(AM), 0.72㎍/ℓ in geometric mean(GM), and blood zinc was 5.07㎎/ℓ in AM, 5.01㎎/ℓ in GM. Age-adjusted blood cadmium was not significant between male(0.93㎍/ℓ in AM, 0.74㎍/ℓ in GM) and female(0.92㎍/ℓ in AM, 0.69㎍/ℓ in GM), and not observed a difference by sex in blood zinc(male :5.07㎎/ℓ in AM, 5.00㎎/ℓ in GM ; female : 5.07㎎/ℓ in AM, 5.02㎎/ℓ in GM). Blood cadmium and zinc were well correlated with age, and had increasing tendency by age group. The positive relation was observed between the level of cadmium and zinc in blood. In summary, these results suggest that blood cadmium of growing students in general population is valuable as an one of indices for body burden of cadmium by pollution.

아드레날린성 효현제에 의한 칼슘 작동성 포타슘 전류의 조절

박운상,이무열,방효원,엄대용 중앙대학교 의과대학 의과학연구소 1995 中央醫大誌 Vol.20 No.4

Smooth muscle is widespread in all viscera and vessels, and presents diverse and different physiological characteristics according to its type(visceral or vascular, etc.), organ, and species. So many scientific attractions are focused on the smooth muscle to know its various physiological properties. In this study mesenteric arterial smooth muscle cell of rabbit was chosen to clarify the regulation mechanism of large conductance Ca-activated K current by adrenergic system. Whole-cell mode of patch clamp technique was used. The results from experimental studies were as follows : 1. In mesenteric arterial smooth muscle cell large oscillartory outward currents were recorded in depolarized state of membrance potential. 2. This outward current was reduced by depletion of intracellular calcium ion. 3. Alpha 1 and 2-adrenergic agonist(phenylephrine, clonidine) and antagonist(prazocin, yohimbin) did not affect these currents. 4. Beta adrenergic agonist(isoproterenol) markedly increased both amplitude and oscillartory characteristics of these currents. The effect of beta adrenergic agonist was almost antagonized by beta antagonist(propranolol). From these results it is suggested that large conductance Ca-activated K currents in mesenteric arterial smooth muscle cells are regulated by β-adrenergic agonist but not by α -adrenergic agonist.

Genus Bacillus의 병원성과 Superoxide Dismutase활성도와의 관계

김환수,정상인,양용태,최철순 중앙대학교 의과대학 의과학연구소 1991 中央醫大誌 Vol.16 No.2

This study was undertaken to examine the possibility of association between pathogenicity of Genus Bacillus and the induction of superoxide dismutase(SOD) activity. In this study, pathogenic B. anthracis ATCC 14578, vaccine strains; Army No.2 and Sterne, and other 4 strains of Bacillus species were included. The induction of SOD of Genus Bacillus was tested after cultivation by candle jar method. The results are summarized as follows: 1. Induction of total SOD activities was observed in pathogenic B. anthracis ATCC 14578 when cultured under reduced oxygen tension(candle jar method). (p>0.05) 2. Nonpathogenic strains, B. anthracis Army No. 2 and Sterne, and other 4 strains of related Bacillus species, were not observed the induction of SOD activity. 3. In the induction experiments, B. anthracis ATCC 14578 showed significant increment of Mn-SOD activity. But, other nonpathogenic strains failed to show statistically significant increase of Mn-SOD activity. These results suggest that the pathogenicity of Genus Bacillus may be associated with inducible activity of SOD.

응급실내원환자의 진단별 차이에 의한 정신의학적 특성에 관한 예비연구

기백석,이재광,박두병 중앙대학교 의과대학 의과학연구소 1995 中央醫大誌 Vol.20 No.1

This study was performed to investigate the relationship between diagnostic differences and psychiatric characteristics among patients who visited emergency room. The subjects were composed of 653 psychiatric patients who visited emergency room Pildong Hospital and Yongsan Hospital, Chung-Ang University from June 1992 to May 1993. Patents charts were reviewed for demographic data(sex, age, residence), mode of arrival(time, season, accompanying person), disposition, manner of discharge, and data were analyzed by Chi-square test using SPSS/PC+program. The summaries of the results were as follows. 1) Anxiety disorder, substance use disorder, epilepsy, and organic brain syndrome were more prevalent in male patients group and somatoform disorder, mood disorder, and psychotic disorder were more prevalent in female patients group. 2) Anxiety disorder, somatoform disorder, mood disorder, and psychotic disorder were specially more prevalent in twenties and thirties patients and organic brain syndrome was more prevalent in forties and fifties patients. 3) Anxiety disorder, somatoform disorder, and mood disorder patients were dominantly treated by OPD follow-up and organic brain syndrome patients were follewed by admission. 4) Anxiety disorder, somatoform disorder, and substance use disorder patients were relatively well compliant to treatment and dischaged under doctor's advice.

소아 비폐색 환자의 수술 전후 비저항치 변화에 대한 연구

한병상,유태선,유영근,홍영호,김춘길,김훈 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.1

Nasal obstruction is one of the most common complaints in pediatric otolarygology. Generally nasal obstruction is caused by anatomic abnormalities of the nasal cavity, inflammation of the nasal from patient to patient. The size of the nasopharyngeal airway and adenoids on the symptom pharygeal wall has been asseaaed by clinical inspection with the posterior rhinoscopy. However, this inspection may be difficult to carry out in childern and has limited value in physiologic aspect. I can measeure the nasal obstruction objectively and raliably with rhinomanometry. 32 patients with nasal obstruction were evaluated preoperatively and postoperativeley. We compared the effects of the two types of surgery by measuring the total nasal resistance(TNR) of rhinomanometry (Rion SR-11) during inspiration. The results were as folloes ; 1) The group who undewent tonsillectomy, adenoidectomy and submucous diatermy had more significant improvement of symptoms than the group who underwent just tosillectomy and adenoidectomy(p<0.05). 2) The preoperative TNR of all the patients during inspiration was 0.360Pa/㎤/sec and 0.275Pa/㎤/sec in postoperative period(p<0.01). The group who underwent tonsillectomy and adenoidectomy had a preoperative TNR OF 0.377Pa/㎤/sec and postoperative TNR OF 0.292Pa/㎤/sec. The group who underwent tonsillectormy, adenoidectormy and submucous diathermy had a preoperative TNR of 0.348Pa/㎤/sec. This changed into a postoperative TNR of 0.261Pa/㎤/sec (p<0.01). 3) This difference of the TNR between preoperative group and postoperative group was statistically significant(P<0.01).

Ouabain이 음경해면체평활근에 미치는 영향에 관한 실험적 연구

오충환,김세철 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.3

The effect of ouabain on smooth muscle of the corpus cavernosum itself and its effect on the action of adrenergic, cholinergic or non-adrenergic non-cholinergic neurotransmitters were observed in vivo using dogs as experimental animals and in vitro using isoloated corpus cavernosal strips from rabbit penis. A 21 gauge needle was placed into the cavernous space of the anethetized dog, and intracorporeal pressure(ICP) was measured; 1) before stimulation of the cavernous nerve(NS), 2) during NS and 3) during NS following intracorporeat injection of ouabain. The corpus cavernosal strip was suspended in an organ both containing 20ml of Krebs-bicarbonate solution main-tained at 37 The Krebs-bicarbonate solution was aerated with 95% oxygen and 5% carbon dioxide. One end of the cavernosal strip was fixed at the bottom of the bath and the other end connected to the force displacement transducer. When the stable tension level of the strip reached, drugs were added to the organ bath and the change of contractility of the strip was recorded on a polygraph. The resist were obtained as follows; 1. ICP before and during NS were 9.806.14mmHg(Mean±S.D.) and 107.80±15.76mmHg. ICP during NS following intracorporeal injection of ouabain was 37.00±12.39mmHg at 10 minutes after injection of ouabain 34.00±1.58mmHg at 50 minutes, 28.80±12.15 mmHg at 90 minutes and 28.40±10.55 mmHg at 130 minutes. There was a significal drop of ICP following intracorporeal injection of ouabain(p<0.01) but a significant change of ICP with the time elapsed after obtain injection was not found. 2. Ouabain (1×10^7M) increased the contractility of the isolated cavernosal strip from rabbit. In the pretreated state with tetrodotoxin(5×10^7M), contraction of the strip was induced by ouabain, but neither relaxation nor contraction occurred by additional nerve stimulation. So, ouabain might contribute to the contraction of cavernosal strip not by neuronal effect but by direct action on the smooth muscle. 3. 2-chloro-adenosine and Vasoactive Intestinal Polypepeide(VIP) showed a relaxing effect on the cavernosal strip but acetylcholine had both contraction and relaxing effect. Ouabain partly inhibited the relaxing effect of these neurotransmitter. Therefore, it is concluded that ouabain directly acts on the smooth muscle of the corpus cavernosum and contracts it. However, it seems that the contraction effect of ouabain is less stronger than the relaxing effect of the adenosine, VIP and acetylcholine.

과배란유도시 난포성숙을 유도시키는 GnRH Agonist가 성선자극 및 호르몬 분비에 미치는 영향에 관한 연구

김중환,이상훈,배도환 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.3

Gonadotropin medications have been used successfully for three decades to stimulate ovarian follicular development in anovulatory patients and , more recently, in normal ovulatory women for assisted reproduction. In these patients, endogenous luteinizing hormone(LH) surge infrequently occureed and therefore the administration of human chorionic gonadotropin(hGG) is required to induce oocyte maturation and ovulation. In spontaneous ovulatory cycle, there is a surge of both luteinzing hormone and follicle stimulation hormone(FSH) at midcycle. But, hCG possesses mainly LH-like activity. In addition, hCG continues to stiumlate the follicles for days after ovulation has been completed due to its long half-life. The objective of this study was to evaluate the efficacy of Gonadotropin releasing hormone(Gn고) agonist to trigger the final follicular maturation in hormone secretions during the ovarian stiumlation. A single dose of decapepty 0.1mg subcutaneously were administered to 40 cycles and 10,000 IU hCG were intramuscularly administered to 38 cycles for triggering the final maturation of oocytes. Both groups underwent identical ovarian stimulation protocol and cycle monitoring. GnRH agonist effectively triggered LH and FSH surge, and which duration was similar that of spontaneous menstrual cycle. In contrast hCG triggered LH surge only, and which duration was longer than that of spontaneous menstrual cycle. No differences were observed in mean serum E_2 and progesterone concentration. Mature oocytes were recovered in all patients. In conclusion, single dose of GnRH-a is able to trigger and adequate midcycle LH/FSH surge, resulting n adequate oocyte maturation and fertilization.

식도암 술식에 있어 개흉술과 경부 식도-위문합술병용의 효과에 관한 추적조사(Ⅰ)

박봉근,안성필,손동섭,이정효 중앙대학교 의과대학 의과학연구소 1999 中央醫大誌 Vol.24 No.1

Carcinoma of the esophagus is one of the most difficult diseases to cure or palliate. Aithough operation may provide the only chance of a cure for esophageal carcinoma, results of the operation still remains unsatisfactory. We performed thoracoabdominal esophagectomy to make a effective radical lymph node dissection, and performed esophagogastrostomy using a transverse cervical incision to make less complication, which are anastomosis site leakage, recurrent laryngeal nerve palsy and so on. We analysed the 7 male patients of esophageal cancer who diagnosed and operated in the manner of thoracoabdominal esophagectomy and esophagogastrostomy using transverse cervical incision at Chung-Ang University Hospital from July, 1995 to June, 1997. Results were as followed The sex incidence showed male predominance with a male to female ratio of 7:o. The main complained symptom is dysphagia for soild food. The tumor was located at lower third in 3 cases, at middle third in 4 cases. According to the AJCC of the primary esophageal cancer, StageⅡ were 3 cases, stageⅢ were 3 cases and StageⅣ was 1 case. In histologic types. most cases of esphoageal cancer were squamous cell carcinoma. As an adjuvant therapy, postoperative chemotherapy and radiotherapy were performed in 3 case, and only a postoperative chemotherapy was performed in 4 cases. Six of the seven patients have been followed up.

가토에서 생검총을 이용한 폐생검후 NBCA 충전에 관한 실험적 연구 : 가토폐 생검 후 NBCA 충전

곽병국,정걸호,최치훈,이창준,장희진,심형진 중앙대학교 의과대학 의과학연구소 1999 中央醫大誌 Vol.24 No.1

Pneumothorax and hemorrhage are frequent complications after percutaneous lung biopsy. The purpose of this study is to evaluate the effects of NBCA on plugging the biopsy tract in rabbit lung and pathologic changes caused by NBCA. The right lungs of 14 New Zealand White rabbit were biopsied with an 18G biopsy gun. The biopsy tracts were filled with none(control group) and NBCA mixed with lipiodol(1:1) in 7 rabbits respectively. CT scans were performed immediatoly and 24 hours after procadure. The rabbits were sacrificed and pathologically cvaluated for 17 days. Each pneumothorax and pulmonary heomrrhage as a complication after gun biopsy was seen in 4 cases (57.1%) of the control group(n=7). In NBCA group(n=7), pneumothorax was seen in 2 cases(28.6%) and hemorrhage was seen in 1 case(14.3%)(p>0.05). NBCA filled the biopsy tract and pleural space, and pleural adhesion was seen in 1 case of 2 rabbits complicated by pneumothorax. Pathologically the hemorrhage was more significant in control group(100%) than in NBCA group(28.6%). But the inflammation was 28.6% in control group and 100% in NBCA group. The necrosis, foreign body reaction and fibrosis were similar in both groups. In conclusion, NBCA would be helpful to prevent the pneumothorax and hemorrhage after a percutaneous lung biopsy.