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Degradation of the Herbicide, TOK(2,4-dichloro-4'-nitro diphenyl ether) in Soil (제초제(除草劑) TOK의 토양중(土壤中) 분해(分解))

  • Lee, Jae-Koo;Kim, Ki-Cheol;Kim, Chang-Han
    • Applied Biological Chemistry
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    • v.23 no.2
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    • pp.131-139
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    • 1980
  • TOK (2,4-Dichlolo-4'-nitrodiphenyl ether) was applied to two Korean soils possessing different physico-chemical properties at a certain concentration and incubated for a certain time under flooded conditions. The metabolites and the soil microorganisms involved in the degradation of TOK are studied. Chong Ju and Chung Ju soils treated with TOK at a concentration of 500 ppm and incubated for two, four, and six months at 30C yielded 4-chloro-4'-amino diphenyl ether, 2, 4-dichloro-4'-amino diphenyl ether(amino-TOK), N-[4'-(4-chloro-phenoxy)] phenyl acetamide, and N-[4'-(4-chloro-phenoxy)] phenyl formamide as the major metabolites. TOK underwent the reduction of nitrogroup to amino group, dechlorination, acetylation, and formylation. No cleavage at the ether linkage was recognized. TOK was more readily degraded in Chung Ju soil which is characterized by the higher pH (PH 6.43), clay loam in textural class, and the higher cation exchange capacity. The toxicity of TOK as a possible environmental contaminant is expected to be considerably reduced as a result of the above degradation Twelve strains of soil bacteria were isolated from the TOK-treated Chong Ju and Chung Ju soils. As a result of the incubation of TOK in pure cultures of the isolates, T-1-1 strain isolated from Chong Ju soil had almost no degradability, whereas T-2-3 strain turned out to be the most potent. The degradation of TOK by the isolates constituted mostly the reduction of the nitro group to amino group. The citrate buffer extract of Chung Ju soil reduced TOK more readily to amino-TOK than that of Chong Ju soil.

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Inhibitory effect of Hypericum ascyron on pro-inflammatory responses in lipopolysaccharide-induced Raw 264.7 Cells (Lipopolysaccharide로 유도된 Raw 264.7 cell에서 물레나물(Hypericum asctron)의 Pro-inflammatory 억제 효과)

  • Hong, Eun-Jin;Park, Hye-Jin;Kim, Na-Hyun;Jo, Jae-Bum;Lee, Jae-Eun;Lim, Su-Bin;Ahn, Dong-Hyun;Jung, Hee-Young;Cho, Young-Je
    • Journal of Applied Biological Chemistry
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    • v.60 no.4
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    • pp.363-372
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    • 2017
  • Hypericum ascyron has long been used as medicinal plant and recent studies reported that H. ascyron has anti-diabetic, anti-oxidant, and anti-bacterial effects. In this study, inhibitory effect from H. ascyron on pro-inflammatory responses has been investigated. H. ascyron was extracted at optimal extraction condition. Total phenolic contents in water and 90% ethanol were 29.75 and 31.82 mg/g, respectively. Hyaluronidase inhibitory activity of H. ascyron extracts (50200μg/mL phenolics) was 0.00-14.81% and 15.33-47.49%, respectively. In cell viability, cell toxicity was shown at concentration of 100μg/mL and 30μg/mL of water and 90% ethanol extract. Therefore, 1050μg/mL in water extracts and 520μg/mL in ethanol extracts was selected each for further study. Inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) and cyclooxygenase (COX)-2-derived prostaglandin E2 (PGE2) protein expression inhibitory effect of extracts were inhibited in a dose dependent manner, significantly. Also, the pro-inflammatory cytokines inhibitory effect such as tumor necrosis factorα, nterleukin (IL)-6 and IL1β were decreased in the dose dependent manner. The results indicate that H. ascyron extracts reduced inflammatory responses in lipopolysaccharide-induced 264.7 cells via the regulation of the iNOS, COX-2, NO, PGE2, and pro-inflammatory cytokines. Therefore, H. ascyron extracts have significant anti-inflammatory effect and a source as therapeutic materials.

Effects of rutin and hesperidin on total cholesterol concentration, transaminase and alkaline phosphatase activity in CCl4 treated rats (루틴과 헤스페리딘이 간 독성을 일으킨 흰쥐의 cholesterol 함량, transaminase, alkaline phosphatase 효소활성에 미치는 영향)

  • Son, Heung-Soo;Kim, Hyun-Sook;Ju, Jin-Soon
    • Applied Biological Chemistry
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    • v.34 no.4
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    • pp.318-326
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    • 1991
  • This study was devised to investigate the effects of flavonoids on carbon tetrachloride toxicity of rats. Through the experiments, the contents of total cholesterol, transaminase(GOT, GPT) and alkaline phosphatase(Alk. P) activities in the liver and serum were determined. The results obtained are summarized as follows; (1) The liver cholesterol concentration of flavonoid injected groups were remarkably increased up to 45% at 2 days after CCl4 injection and then the values were almost recovered to the level of control group at 4 days after CCl4 injection. The increase of serum cholesterol content was inhibited by the flavonoids after CCl4 injection, but the result was not significant. (2) Flavonoids injection was found to have the ability to decrease the elevated serum GOT, Alk. P activities resulting from injection of CCl4 and induce rapid recovery from such an elevated level and the extent of such a decreasing action was greatest in hesperidin injection group. The liver microsomal Alk. P and GOT activities were not affected by the treatment of flavonoids. (3) The elevated serum and liver microsomal GPT activities induced by CCl4 injection were inhibited by the injection of flavonoids.

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Effects of Nitrogen Sources on RNA, DNA and other Phosphorus Fractions of Soybean Cultivars Different in Phosphorus Sensitivity (인산감수성(燐酸感受性)이 다른 대두품종(大豆品種)의 RNA, DNA 및 기타 인산형태(燐酸形態)에 대(對)한 질소원(窒素源)의 영향(影響)에 관한 연구(硏究))

  • Park, Hoon;Stutte, Charls A.
    • Applied Biological Chemistry
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    • v.19 no.3
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    • pp.172-183
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    • 1976
  • RNA, DNA and other phosphorus fractions were determined in the leaf and root of soybean plants different in phosphorus sensitivity grown in NH4N,NO3N and urea medium. The phosphorus sensitive cultivars contained higher ASIP (acid soluble inorganic phosphorus) than the tolerant cultivars with all nitrogen sources. ASIP was highest in the urea treated plants and lowest in the nitrate treated plants. Total phosphorus content was mostly affected with increase in ASIP. When ASIP increased, acid solsuble organic phosphorus(ASOP), phospholipids (L-P), RNA-P, residual phosphorus (R-P) tended to increase, while DNA-P showed little change. The percent RNA-P or DNA-P of total phosphorus in the nitrate treated plant was twice that in the ammonium treated plant, which were also higher in tolerant cultivars regardless of nitrogen sources. The percent ASOP in total acid soluble phosphorus (ASOP/ASP×100) decreased as phosphorus sensitivity decreased. Indications are that phosphorus sensitivity depends on the relative sizes of phosphorus metabolic pools. Total dry matter yield was negatively correlated with total phosphorus (r=0.84 significant at 0.01P), ASIP (0.84 significant at 0.01P) and residual phosphorus (0.69 significant at 0.05P). ASOP showed positive correlation with L-P, RNA-P and DNA-P but negative with R-P. RNA-P was significanly correlated only with L-P (0.63 at P=0.01). There was significant interaction (0.01) among nitrogen sources, cultivars and phosphorus metabolic pools. Phosphorus sensitivity and ammonium toxicity appear to be same in view of energy metabolism, that is, the former inhibits the conversion of ATP to ADP (energy releasing) through phosphate potential while the latter inhibits ATP formation (energy storing).

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On the Utilization of Inactive BHC isomers -Synthesis of 3-(2,4,5-trichlorophenyl)-1-methyl urea as a herbicide- (BHC 이성질체(異性質體)의 활용(活用)에 관(關)한 연구(硏究) -제초제(除草劑)로서 3-(2,4,5-trichlorophenyl)-1- methyl urea의 합성(合成)-)

  • Lee, Kyu-Seung;Park, Chang-Kyu
    • Applied Biological Chemistry
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    • v.22 no.2
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    • pp.109-122
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    • 1979
  • Present study was carried out to reduce residual toxicity of BHC insecticides inherent in the organochlorine pesticides. For This end, r-isomer, the most potent insecticidal component among the BHC stereoisomers, was isolated and thus fortified by means of solvent precipitation. In parallel, 3-(2,4,5-trichlorophenyl)-1-methyl urea was prepared in good yield from technical BHC via 1,2,4-trichlorobenzene, 1,2,4,-trichloronitrobenzene, and 2,4,5-trichloroaniline. In addition, certain merit of the compound which make it possible to use as a herbicide is discussed. The results are summarized as follows; 1. Recrystallizing technical BHC from methanol-water binary solvent system, r-isomer was enriched to 49.7% at 95% recovery of r-isomer. 2. By partitioning technical BHC in 85% of methanolic solution into chloroform, r-isomer was fortified to 89.6% at 90.5% recovery of r-isomer. 3. Yield of 1,2,4-trichlorobenzene from technical BHC was greatly dependent upon concentration of alkalies and to less degree on the alkalies. 4. Surfactants, in particular cationic a quartenary ammonium salt, increased yield of 1,2,4-trichlorobenzene from technical BHC by alkaline hydrolysis. 5. Conversion of 1,2,4-trichlorobenzene to 2,4,5-trichloronitrobenzene was effected almost quantitatively utilizing HNO3H2SO4 nitrating agent at low temperature. 6. Yield of 91.4% was observed for the synthesis of 2,4,5-trichloroaniline by reducing 2,4,5-trichloronitrobenzene in the presence of iron turning and hydrochloric acid. 7. Overall yield based on BHC of 3-(2,4,5-trichlorophenyl)-1- methyl urea was 60.8%. 8. Inhibition effects, both germination and growth, 3-(2,4,5-trichlorophenyl)-1-methyl urea on several crops were found comparable to or more potent than those of linuron®anddiuron®. In addition, it was also noted that susceptibility to the prepared compound depended upon the crops as well as specific part (shoots, roots) of the plant exposed to the chemicals.

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Effect of soil stabilizer on the bioavailability of arsenic in paddy soil (안정화제가 논토양 내 비소의 생물유효도에 미치는 영향)

  • Ji-Hyock Yoo;Hui-Seon Kim;Mi-jin Kim;Jung-Ok Woo;Ho-yang Choi;Sung-Chul Kim
    • Journal of Applied Biological Chemistry
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    • v.65 no.4
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    • pp.349-355
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    • 2022
  • In this study, we sought to identify a soil stabilizer that can be applied to paddy fields vulnerable to arsenic (As) pollution. To this end, we conducted a pot experiment in which we evaluated the effects of different stabilizers on the bioavailability of As in paddy soil. As candidate stabilizers, we assessed calcium superphosphate (CSP), sulfur, and steel slag, which were applied at the rates of 0.7 and 1.4, 0.1 and 0.2, and 7.0 and 14.0 Ma ha-1, respectively. On day 67 after rice transplantation, we detected significantly lower concentrations of As in the solutions of paddy soil treated with 1.4 Ma ha-1 CSP (96.9 ㎍ L-1) and 0.2 Ma ha-1 sulfur (207.2 ㎍ L-1) compared with the As concentrations in control (314.5 ㎍ L-1) and steel slag-treated (268.6-342.4 ㎍ L-1) soil. Compared with the As concentrations in control brown rice (0.16 mg kg-1), concentrations in brown rice were lowest in the pots treated with 1.4 Ma ha-1 CSP (0.09 mg kg-1). Furthermore, in response to CSP treatments, we detected increases in the weight of rice grains (50.0-50.4 g/pot) compared with the control (40.4 g/pot) and other treatments (26.9-48.1 g/pot), which we speculate could be attributed to the reduction in As toxicity to rice owing to a decline in soil solution As contents and the fertilization effect of the CSP treatment. Collectively, our findings indicate a high-level application of CSP (1.4 Ma ha-1) to paddy soil has a comparatively beneficial effect in mitigating the bioavailability of As.

Pharmacological Studies of Cefoperazone(T-1551) (Cefoperazone(T-1551)의 약리학적 연구)

  • Lim J.K.;Hong S.A.;Park C.W.;Kim M.S.;Suh Y.H.;Shin S.G.;Kim Y.S.;Kim H.W.;Lee J.S.;Chang K.C.;Lee S.K.;Chang K.C.;Kim I.S.
    • The Korean Journal of Pharmacology
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    • v.16 no.2 s.27
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    • pp.55-70
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    • 1980
  • The pharmacological and microbiological studies of Cefoperazone (T-1551, Toyama Chemical Co., Japan) were conducted in vitro and in vivo. The studies included stability and physicochemical characteristics, antimicrobial activity, animal and human pharmacokinetics, animal pharmacodynamics and safety evaluation of Cefoperazone sodium for injection. 1) Stability and physicochemical characteristics. Sodium salt of cefoperazone for injection had a general appearance of white crystalline powder which contained 0.5% water, and of which melting point was 187.2C. The pH's of 10% and 25% aqueous solutions were 5.03 ana 5.16 at 25C. The preparations of cefoperazone did not contain any pyrogenic substances and did not liberate histamine in cats. The drug was highly compatible with common infusion solutions including 5% Dextrose solution and no significant potency decrease was observed in 5 hours after mixing. Powdered cefoperazone sodium contained in hermetically sealed and ligt-shielded container was highly stable at 4^circ}C{\sim}37^{\circ}C for 12 weeks. When stored at 4C the potency was retained almost completely for up to one year. 2) Antimicrobial activity against clinical isolates. Among the 230 clinical isolates included, Salmonella typhi was the most susceptible to cefoperazone, with 100% inhibition at MIC of 0.5μg/ml. Cefoperazone was also highly active against Streptococcus pyogenes(group A), Kletsiella pneumoniae, Staphylococcus aureus and Shigella flexneri, with 100% inhibition at 16μg/ml or less. More than 80% of Escherichia coli, Enterobacter aerogenes and Salmonella paratyphi was inhibited at 16μ/ml, while Enterobacter cloaceae, Serratia marcescens and Pseudomonas aerogenosa were somewhat less sensitive to cefoperagone, with inhibitions of 60%, 55% and 35% respectively at the same MIC. 3) Animal pharmacokinetics Serum concentration, organ distritution and excretion of cefoperazone in rats were observed after single intramuscular injections at doses of 20 mg/kg and 50 mg/kg. The extent of protein binding to human plasma protein was also measured in vitro br equilibrium dialysis method. The mean Peak serum concentrations of 7.4μg/ml and 16.4μ/ml were obtained at 30 min. after administration of cefoperazone at doses of 20 mg/kg and 50 mg/kg respectively. The tissue concentrations of cefoperazone measured at 30 and 60 min. were highest in kidney. And the concentrations of the drug in kidney, liver and small intestine were much higher than in blood. Urinary and fecal excretion over 24 hours after injetcion ranged form 12.5% to 15.0% in urine and from 19.6% to 25.0% in feces, indicating that the gastrointestinal system is more important than renal system for the excretion of cefoperazone. The extent of binding to human plasma protein measured by equilibrium dialysis was 76.3, which was somewhat lower than the others utilizing centrifugal ultrafiltration method. 4) Animal pharmacodynamics Central nervous system : Effects of cefoperazone on the spontaneous movement and general behavioral patterns of rats, the pentobarbital sleeping time in mice and the body temperature in rabbits were observed. Single intraperitoneal injections at doses of 5002,000mg/kg in rats did not affect the spontaneous movement ana the general behavioral patterns of the animal. Doses of 125500mg/kg of cefoperazone injected intraperitonealy in mice neither increased nor decreased the pentobarbital-induced sleeping time. In rabbits the normal body temperature was maintained following the single intravenous injections of 1252,000mg/kg dose. Respiratory and circulatory system: Respiration rate, blood pressure, heart rate and ECG of anesthetized rabbits were monitored for 3 hours following single intravenous injections of cefoperazone at doses of 1252,000mg/kg. The respiration rate decreased by 3l7 at all the doses of cefoperazone administered. Blood pressure did not show any changes but slight decrease from 130/113 to 125/107 by the highest dose(2,000 mg/kg) injected in this experiment. The dosages of 1,000 and 2,000 mg/kg seemed to slightly decrease the heart rate, but it was not significantly different from the normal control. All the doses of cefoperazone injected were not associated with any abnormal changes in ECG findings throughout the monitering period. Autonomic nervous system and smooth muscle: Effects of cefoperazone on the automatic movement of rabbit isolated small intestine, large intestine, stomach and uterus were observed in vitro. The autonomic movement and tonus of intestinal smooth muscle increased at dose of 40μg/ml in small intestine and at 0.4 mg/ml in large intestine. However, in stomach and uterine smooth muscle the autonomic movement was slightly increased by the much higher doses of 5-10 mg/ml. Blood: In vitro osmotic fragility of rabbit RBC suspension was not affected by cefoperazone of 110mg/ml. Doses of 7.5 and 10 mg/ml were associated with 11.8% and 15.3% prolongation of whole blood coagulation time. Liver and kidney function: When measured at 3 hours after single intravenous injections of cefoperaonze in rabbits, the values of serum GOT, GPT, Bilirubin, TTT, BUN and creatine were not significantly different from the normal control. 5) Safety evaluation Acute toxicity: The acute toxicity of cefoperazone was studied following intraperitoneal and intravenous injections to mice(A strain, 4 week old) and rats(Sprague-Dawler, 6 week old). The LD_(50)'s of intraperitonealy injected cefoperazone were 9.7g/kg in male mice, 9.6g/kg in female mice and over 15g/kg in both male and female rats. And when administered intravenously in rats, LD_(50)'s were 5.1g/kg in male and 5.0g/kg in female. Administrations of the high doses of the drug were associated with slight inhibition of spontaneous movement and convulsion. Atdominal transudate and intestinal hyperemia were observed in animals administered intraperitonealy. In rats receiving high doses of the drug intravenously rhinorrhea and pulmonary congestion and edema were also observed. Renal proximal tubular epithelial degeneration was found in animals dosing in high concentrations of cefoperazone. Subacute toxicity: Rats(Sprague-Dawley, 6 week old) dosing 0.5, 1.0 and 2.0 g/kg/day of cefoperazone intraperitonealy were observed for one month and sacrificed at 24 hours after the last dose. In animals with a high dose, slight inhibition of spontaneous movement was observed during the experimental period. Soft stool or diarrhea appeared at first or second week of the administration in rats receiving 2.0g/kg. Daily food consumption and weekly weight gain were similar to control during the administration. Urinalysis, blood chemistry and hematology after one month administration were not different from control either. Cecal enlargement, which is an expected effect of broad spectrum antibiotic altering the normal intestinal microbial flora, was observed. Intestinal or peritoneal congestion and peritonitis were found. These findings seemed to be attributed to the local irritation following prolonged intraperitoneal injections of hypertonic and acidic cefoperazone solution. Among the histopathologic findings renal proximal tubular epithelial degeneration was characteristic in rats receiving 1 and 2g/kg/day, which were 10 and 20 times higher than the maximal clinical dose (100 mg/kg) of the drug. 6) Human pharmacokinetics Serum concentrations and urinary excretion were determined following a single intravenous injection of 1g cefoperazone in eight healthy, male volunteers. Mean serum concentrations of 89.3, 61.3, 26.6, 12.3, 2.3, and 1.8μg/ml occured at 1,2,4,6,8 and 12 hours after injection respectively, and the biological half-life was 108 minutes. Urinary excretion over 24 hours after injection was up to 43.5% of administered dose.

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Effect of Cd2+ on the Oocyte Maturation and Developmental Stages of Brown Frog Embryo, Rana dybowskii in vitro (Cd2+이 북방산개구리의 난자성숙과 배아발달에 미치는 영향)

  • Ko Sun-Kun
    • Korean Journal of Environment and Ecology
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    • v.20 no.3
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    • pp.345-351
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    • 2006
  • This study investigates the toxic effects of Cd2+on frog (Rana dybowskii) by the determination of oocyte maturation and development of embryo exposure to different concentrations of the toxicant. The results show that Cd2+ concentration of 0.1ppm suppressed the maturation of the oocytes. To examine the reversibility of the inhibitory effects, the oocytes were exposed to the Cd2+ only for 3 hours, and then transferred to plain medium and cultured further for 17 hours. The oocytes were recovered from the toxic effect of the Cd2+ when they were exposed to 1ppm, but not to 2.5ppm of the Cd2+. The development of 2 cell embryos to 32 cell was completely suppressed at 0.1ppm and the longer the embryos were exposed to the Cd2+, the more damage appeared to the embryos and the cytolysis of the 32 cell was induced by Cd2+ at 0.1ppm. On the other hand, the embryos of blastula stage were cultured 96 hours in presence of the Cd2+ at various concentrations and were examined. The rates of mortality and malformed larvae were investigated by probit analysis. From the results of LC50 of 0.1ppm and EC50 of 0.08ppm, Tl of 5.0 was derived, which indicates Cd2+ is to be considered a teratogenic compound. Such specific malformations occurred in 14.3% as spine deformations at the 0.05ppm, in 75.0% as tail deformations at the 0.1ppm, in 66.7% as abdominal deformations at the 0.01ppm and in 26.0% as profound deformations at the 0.1ppm of Cd2+ concentration which living embryos were exposed to. Cd2+ suppressed growth to head-tail length at 0.1ppm. In conclusion, The study results reveal that Cd2+ must be considered highly toxic effect to oocyte maturation and embryonic development.

The effect of chitosan/ACS on bone regeneration in rat calvarial defects (백서두개골 결손부에서 키토산/흡수성 콜라겐 전달체의 골재생)

  • Kim, Soo-Kyoung;Suk, Hun-Joo;Kim, Chang-Sung;Cho, Kyoo-Sung;Chai, Jung-Kiu;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.33 no.3
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    • pp.457-474
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    • 2003
  • The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

Effect of Lead Acetate on Pancreatico-biliary Secretion (납(Lead)이 취외분비 기능에 미치는 영향)

  • Sheen, Yhun-Yhong;Kim, Won-Joon
    • The Korean Journal of Pharmacology
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    • v.17 no.1 s.28
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    • pp.17-25
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    • 1981
  • No evidence has accumulated that lead compound is an essential component for biological function in animals. Lead is absorbed primarily through the epithelial mucosal cells in duodenum and the absorption can be enhanced by the substances which bind lead and increase its solubility. Iron, zinc and calcium ions, however, decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. Therefore, the absorption of lead is increased in iron deficient animals. Lead shows a strong affinity for ligands such as phosphate, cysteinyl and histidyl side chains of proteins, pterins and porphyrins. Hence lead can act on various active sites of enzymes, inhibiting the enzymes which has functional sulfhydryl groups. lead inhibits the activity of δ-aminolevulinic acid dehydratase for the biosynthesis of hemoproteins and cytochrome, which catalyzed the synthesis of monopyrrole prophobilinogen from δ-aminolevulinic acid. Accordingly lead decrease hepatic cytochrome p-450 content, resulting an inhibition of the activity of demethylase and hydroxylase in liver. Little informations are available on the effect of lead on digestive system although the catastrophic effects of lead intoxication are well documented. The present study was, therefore, attempted to investigate the effect of lead on pancreaticobiliary secretion in rats. Albino rats of both sexes weighing 170230g were used for this study. The animals were divided into one control and three treated groups, i.e., control (physiologic saline 1.5ml/kg i.p.), lead acetate (l0μmole/kg/dayi.p.), Pb(Ac)2 and EDTA(each10μmole/kg/dayi.p.), Pb(Ac)2 and FeSO4(eachl0μmole/kg/dayhp). The pancreatico-biliary juice was collected under urethane anesthesia, and activities of amylase and lipase were determined by employing Sumner's and Cherry and Crandall's methods. The summarized results are follows. 1) In the experiment for acute toxicity of lead acetate, 20% of mortality was observed in rat treated with lead acetate as well as inhibition of the activity of amylase in the juice at the 3 rd day of the treatment. 2) No increases in body weight were observed in rats treated with lead acetate, while in control group the significant increases were observed. However, the body weights of animals were increased in the group lead acetate plus EDTA or FeSO4. 3) Lead acetate decreased significantly the volume of pancreatico-biliary juice whereas additional treatment of EDTA and FeSO4 prevented it. 4) Total activity of amylase was markedly reduced due to lead acetate treatment, but no change was showed following additional treatment with EDTA and FeSO4. 5) No changes in the cholate and lipase output were observed in rats treated with lead acetate as compared with that of control rats. 6) Increase in bilirubin output in rats treated with lead acetate was shown on the 2nd and 3rd weeks treatment. 7) In the case of in vitro experiment, lead acetate also markedly inhibited release of amylase from pancreatic fragment. 8) Histologic finding indicated that acini vacuolation was induced in the pancreatic tissue of rat treated with lead acete. From the above results, it might be concluded that lead acetate decreases the volume of pancreatico-biliary secretion and inhibits the amylase activity, by acting directly on pancreatic cells.

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