Therapeutic effect of low molecular weight chitosan containing sepia ink on ethanol-induced gastric ulcer in rats

ABSTRACT PURPOSE: To evaluate the role of low molecular chitosan containing sepia ink (LMCS) in ethanol-induced (5 ml/kg) gastric ulcer in rats. METHODS: Animals were divided into four groups (n = 12): normal group (Normal), negative control group (Con), experiment group (LMCS) and positive control Omeprazole group (OMZ). Gastric empty rate was detected in the first 7 days. Rats were sacrificed at 7, 14 and 21 day for histology and ELISA detections. RESULTS: Gastric empty was no significant differences among the groups (P > 0.05). Histological observation showed gastric mucosal LMCS treated had better healing effect. Hydroxyproline (Hyp) was significantly increased from 7 day (P < 0.05). LMCS significantly inhibited malondialdehyde (MDA) generation for lipid peroxidation from 7 day (P < 0.05). LMCS significantly promoted the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) at the earlier stage (P < 0.05). OMZ had the similar effects above. As for myeloperoxidase (MPO), LMCS significantly decreased and restored it to normal levels from 7 day (P < 0.05), it is earlier than OMZ which is from 14 day. CONCLUSION: LMCS can improve gastric mucosa tissue repair, exert significant influences on oxidative and antioxidant enzyme activities and neutrophil infiltration.

Effects of platelet rich plasma on fascial healing in rats with fecal peritonitis

ABSTRACT PURPOSE : To evaluate the effects of platelet rich plasma (PRP) on the healing of fascia wherein peritonitis has been created. METHODS: Twenty eight Wistar Albino rats were divided into four groups. Only a primary fascial repair following laparotomy was performed on Group 1, a primary fascial repair performed and PRP treatment applied following laparotomy on Group 2, and a fecal peritonitis created following laparotomy and a primary fascial repair carried out on Group 3. A fecal peritonitis was created following laparotomy and primary fascial repair and PRP treatment on the fascia was carried out on Group 4. RESULTS: TNF-α was found to be significantly lower in the control group (Group 1). It was detected at the highest level in the group in which fecal peritonitis was created and PRP applied (Group 4). TGF-β was determined as being significantly higher only in Group 4. Histopathologically, the differences between the groups in terms of cell infiltration and collagen deposition were not found to be significant. CONCLUSION: When platelet rich plasma was given histologically and biochemicaly as wound healing parameters cellular infiltration, collagen accumulation, and tissue hydroxyiproline levels were not increased but neovascularization, fibroblast activation and TNF Alfa levels were increased and PRP accelerated wound healing.

Effects of chitin and sepia ink hybrid sponge on the healing of burning wound rats and its impact on macrophages in vitro

PURPOSE: To detect whether chitin and sepia ink sponge (CS) can promote wound healing and elevate impact of CS on phagocytosis ability of macrophages. METHODS: Forty-eight rats were assigned to four groups: Normal group (Normal), negative control group (Con), chitin and sepia ink sponge group (CS) and positive control Surgicel Gauze(r) group (SG). Deep second-degree burn model was created in rats. Wound area was recorded by digital imaging and determined using Image J software. Samples were collected and kept at -80oC on 3d, 7d, 14d and 21d for cytokines detecting. Transforming growth factor (TGF)-β1, interleukin (IL)-6, matrix metalloproteinase (MMP)-1, hydroxyproline (Hyp) and macrophage activity reflected by tumor necrosis factor (TNF)-α were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Comparing to Con and SG, scabs in CS group fell off and basically healed on 21 day. TGF-β1, IL-6, MMP-1 and Hyp were significantly increased by CS and SG comparing to Con (p < 0.05), CS had more apparently adjustment on TGF-β1 and MMP-1 compared to SG; results in vitro indicated CS significantly promoted phagocytosis ability of macrophages reflected in TNF-α (p < 0.05). CONCLUSION: CS improved wound healing through exerting significant influences on secretion of kinds of cytokines and activating macrophages.

Passive Skeletal Muscle Excursion after Tendon Rupture Correlates with Increased Collagen Content in Muscle

PURPOSE: This study was designed to measure time-dependent changes in muscle excursion and collagen content after tenotomy, and to analyze the correlation between muscle excursion and collagen content in a rabbit model. MATERIALS AND METHODS: Twenty-four rabbits underwent tenotomy of the second extensor digitorum longus (EDL) muscles on the right legs and were randomly assigned to three groups based on the period of time after tenotomy (2, 4, and 6 weeks). The second EDL muscles on left legs were used as controls. At each time after tenotomy, passive muscle excursion and collagen content, determined by hydroxyproline content, were measured bilaterally, and the ratio of each value to the normal one was used. RESULTS: The mean ratio of muscle excursion after tenotomy to the value of the control decreased in a time-dependent fashion: 92.5% at 2 weeks, 78.6% at 4 weeks, and 55.1% at 6 weeks. The mean ratio of hydroxyproline content in muscle to the value of the control increased in a time-dependent fashion: 119.5% at 2 weeks, 157.3% at 4 weeks, and 166.6% at 6 weeks. There was a significant negative correlation between the ratio of hydroxyproline content in muscle after tenotomy to the control values and the ratio of muscle excursion after tenotomy to the control values (r=-0.602, p=0.002). CONCLUSION: The decrease in muscle excursion seems to correlate with the increase in collagen content in the muscle in a time-dependent fashion following tenotomy.

Effect of sodium fluoride and magnesium chloride on different hydroxyproline fractions in rat liver.

Sodium fluoride (NaF) is used for prevention of caries in the form of fluoridated drinking water, fluoride tablets etc. In the present study, the effect of NaF-induced alterations in hydroxyproline (Hyp) and collagen was investigated in rat liver. The effect of pretreatment with MgCl2 on NaF-induced changes in liver Hyp and collagen was also studied. The NaF treatment at 5, 10 and 20 mg/kg body wt (reported LD50 of NaF being 24 mg/kg body wt through intraperitoneal route) caused a significant decrease in free Hyp (P<0.05), when compared to control rats. The rats treated with 20 mg/kg body wt of NaF showed a significant increase in protein-bound Hyp (P<0.001), as compared to control group, while of NaF treatment at 5 and 10 mg/kg body wt caused no significant change in protein-bound Hyp. All the doses of NaF had no significant effect on peptide-bound and total Hyp and total collagen. Treatment of with MgCl2 alone (30 mg/kg body wt) or with NaF (10 mg/kg body wt) caused a significant decrease in free Hyp (P<0.05). MgCl2 alone and with NaF caused a significant increase (P<0.05) in total collagen content. Thus, the present study demonstrated that NaF had no significant effect on total Hyp and collagen, indicating that its use in various products may not interfere with the liver collagen.

Inhibitory Effect of Angiotensin Blockade on Hepatic Fibrosis in Common Bile Duct-ligated Rats / 대한간학회지

BACKGROUNDS AND AIMS: Angiotensin receptors are found on hepatic stellate cells, which participate in hepatic fibrosis. Therefore, it is presumed that angiotensin has a role in hepatic fibrosis. The aim of this study was to evaluate the effects of angiotensin blockade on inhibition of hepatic fibrosis in cirrhotic rat model. Material and METHODS: Cirrhosis with portal hypertension was produced by common bile duct ligation (BDL) in the adult Sprague-Dawley rats. They were classified into 4 groups (each group n=6) as follows; G1: BDL without drug, G2: BDL+captopril 100 mg/kg/day beginning 2 weeks after BDL, G3: BDL+captopril 100 mg/kg/day, starting just after BDL, G4: BDL+losartan 10 mg/kg/day, starting just after BDL. After 4 weeks following BDL, hepatic fibrosis was histomorphologically analyzed by Batts & Ludwig score. Alpha smooth muscle actin by immunohistochemical stain, hydroxyproline contents of liver tissue by spectrophotometry and expression of collagen, procollagen, and TGF-beta by real-time PCR were measured. RESULTS: Batts & Ludwig score were 3.8, 3.0, 2.6,and 2.6 in G1, G2, G3, and G4, respectively. The expression of alpha-SMA was significantly lower in G3 and G4 than in G1; 11.9%, 10.9%, 2.6%, and 1.1% in G1, G2, G3, and G4, respectively (p<0.05). The concentration of hydroxyproline (microgram/g liver tissue) was lower in G3 and G4 compared with G1 (p<0.05). Also, the administration of angiotensin blockade just after BDL significantly reduced the expression of collagen, procollagen, and TGF-beta mRNA. CONCLUSIONS: Angiotensin blockades are effective in the prevention of hepatic fibrosis in BDL rats.

Effect of nifedipine and amlodipine on dead space wound healing in rats.

Effect of two calcium channel blockers (CCBs) nifedipine and amlodipine, was studied on normal and steroid depressed wound healing in albino rats, using the dead space wound model. The drugs enhanced normal healing as evidenced by increase in tensile strength of 10 days old granulation tissue. There was neither a significant change in the hydroxyproline level (or collagen) nor a change in the glycosaminoglycan content in granulation tissue. However, lysyloxidase level was increased significantly. The increase in tensile strength could thus be attributed to better cross-linking and maturation of collagen rather than collagen synthesis per se. The drugs were also able to overcome steroid depressed wound healing. It is likely that the prohealing effects may be related to the improved antioxidant status too, since superoxide dismutase levels were observed to be higher in the CCB- treated animals.

The effect of GM-CSF (granulocyte macrophage colony stimulating factor) on doxorubicin induced tissue necrosis and wound healing.

PURPOSE: The effect of GM-CSF (granulocyte macrophage-colony stimulating factor) on tissue necrosis and ulceration induced with doxorubicin extravasation was studied. MATERIALS AND METHODS: Adult Wistar-Albino rats (n=36) were used in the study. Doxorubicin (0.4mg/300 g) was applied subcutaneously to abdominal wall. In group I (n=18), half hours after doxorubicin injection, GM-CSF 6 microg/300 mg was applied subcutaneously to the same localization. In group II (n = 18) same amount of physiologic saline (0.5 ml) were given subcutaneously to the injection site (as vehicle control groups). Group II and I were examined for induration or ulceration on 7th and 21st day. After evaluating the lesions, the injection sites were excised. Hydroxyproline (5-HP) values of dry tissue samples were calculated and histopathologic examination was done. RESULTS: At day seven there were four and eight ulceration in groups I and II, while there were four and 14 ulceration in the second evaluation at day 21st (p<0.05). 5-HP values of the groups were as follows. 97.43+/-20.39 in group land 91.34+/-22.26 in group II. Although there was an increase in epithelization, eosinophil and lymphocyte infiltration and mast cell number in group I in histopathologic examinations only the increase in angiogenesis in group I was found to be statistically significant (p<0.05). CONCLUSION: It can be concluded that GM-CSF may have beneficial effect in the treatment of doxorubicin induced tissue necrosis.

Effect of Hepatogard--an indigenous formulation on dexamethasone induced antihealing effects in male albino rats.

Hepatogard, is a multi-ingredient phytopharmaceutical product containing crude powders of eleven plants. Its effect on the different parameters of wound healing was assessed alone and in the presence of dexamethasone. The parameters chosen for the study were the breaking strength of incised wound, breaking strength of granulation tissue and hydroxyproline content. The result showed that Hepatogard increased the breaking strength of granulation tissue but not of incised wound. It reversed the dexamethasone induced decrease in breaking strength in both incised wound and granulation tissue. Even though it had no effect of its own on hydroxyproline concentration, it reversed the dexamethasone induced decrease in the hydroxyproline content of granulation tissue. Thus, Hepatogard has the potential for antagonizing the antihealing effect of steroids in patients receiving steroid therapy.

Hepatic fibrogenesis using chronic arsenic ingestion: studies in a murine model.

Chronic oral arsenic (As) ingestion has been alleged to cause hepatic fibrosis, non-cirrhotic portal fibrosis and cirrhosis of the liver. The present study was aimed to investigate if hepatic fibrogenesis and non-cirrhotic portal fibrosis (NCPF) is caused by arsenic. A significant increase in the hepatic protein and collagen was seen compared with controls; hepatic 4-hydroxyproline levels, indicative of fibrogenesis, were increased 4-14 folds with different dosages of arsenic compared to the controls. Hepatocellular necrosis and inflammation were negligible to mild in all the groups. None of the animals developed significant splenomegaly or features of non-cirrhotic portal hypertension. The results suggest that (i) prolonged oral arsenic ingestion in mice leads to significant hepatic fibrogenesis and collagen synthesis with minimal hepato-cellular injury; (ii) arsenic ingestion alone is unlikely to cause non-cirrhotic portal fibrosis or cirrhosis of liver. This murine model of arsenic feeding could be used for the evaluation of new antifibrotic agents for the liver.

Evaluation of the degree of cross-linking in UV irradiated porcine valves

A porcine heart valve was irradiated by Ultraviolet (UV) rays (10 W, 254 nm) for 2, 4, 8 and 24 hours at 4 degrees C to cross-link the structural collagen matrix. The degree of cross-linking was evaluated by assaying the released amount of hydroxyproline (Hyp) from the matrix, and comparing it with the positive controls of valves treated by glutaraldehyde (GA) solution (0.625 wt%) and the negative controls of non-treated fresh valves. The undigested weight ratio of the specimens increased by increasing the UV irradiation time. The undigested weight of the leaflets, tunica interna and tunica externa of the fresh, GA-treated and UV-irradiated specimens after collagenase digestion was compared. As UV irradiation increased, the amount of released hydroxyproline was gradually decreased until 8 hours of irradiation, after which the released hydroxyproline-reduction occurred slightly until 24 hours of irradiation time in this system. A total 47.68% of the hydroxyproline in the valve was cross-linked by UV irradiation after 24 hours, while 73.74% of the hydroxyproline in the positive control was crossed-linked. Light microscopic observation revealed that the typical crimp pattern of collagen fibers decreased and was rearranged into a dense flattened pattern as the UV irradiation induced interfibrilar cross-linking. GA-treated valves demonstrated a denser matrix pattern than the UV-irradiated specimens. Cross-linked collagenous tissue prepared by UV irradiation would be useful for improving durability and reducing the disadvantages related to using a chemical cross-linking agent.

Papel del hueso en la fisiopatologia de la hipercalciuria idiopatica: efecto del aminobisfosfonato alendronato / Role of the bone in the physiopathology of idiopathic hypercalciuria: effect of amino-bisphosphonate alendronate

Estudios previos de nuestro laboratorio han demonstrado una disminución del contenido mineral del hueso y una correlación entre la disminución del contenido mineral y la producción de distintas citoquinas que intervienen en el proceso de resorción ósea. Al mismo tiempo, observamos que el tratamiento a corto plazo con alendronato produce una disminución del calcio urinario en pacientes con hipercalciuria idiopática. En el presente estudio analizamos los efectos del alendronato a largo plazo (10 mg/día por un año) sobre el calcio y la hidroxiprolina urinaria y el contenido mineral óseo en 18 hipercalciúricos y 8 normocalciúricos con litiasis urinaria. Las características clínicas, así como la distribución por edades y sexo fue similar en ambos grupos. En calcio urinario disminuyó significativamente al final del primer mes y continuó bajo posteriormente (277 + 28, antes vs. 202 + 26 mg/g creatinina, después de 12 meses con alendronato, p<0.01). La hidroxiprolina urinaria disminuyó significativamente durante el estudio (125,5 + 32.1 vs. 39.66 + 17.5 mg/g creatinina, p<0.05). El calcio sérico, la filtración glomerular y el sodio urinario no se modificaron durante el estudio. La densidad mineral ósea en columna lumbar, determinada por densitometría por rayos X, se incremento significativamente el primer año de 1.162 + 0.231 a 1.197 + 0.248 g/cm2 (p<0.01). No se observaron cambios en la densidad mineral del cuello de fémur. Estos cambios se asociaron a una disminución en la transcripción del mRNA para IL-1 alpha, determinados por la reacción en cadena de polimerase (PCR), en células mononucleares no estimuladas. Los sujetos normocalciúricos no demostraron cambios significativos en la excreción urinaria de calcio. En resumen, los cambios observados en el calcio urinario y otros parámetros metabólicos óseos sugieren un papel importante del hueso en la fisiopatología de la hipercalciuria idiopática.

Changes in hydroxyproline levels in electric field tissue interaction.

Guinea pigs when exposed to external electric field (1.9 kV/m) for 9 hrs/day for 3 days registered rise in the levels of hydroxyproline in liver, lung and kidney, suggesting increased synthesis of collagen.

Intestinal healing in protein malnutrition and peritoneal infection in rats

O estudo da evoluçäo da cicatrizaçäo de anastomoses intestinais foi realizado em ratos submetidos a infecçäo peritoneal ou a desnutriçäo protéica. O grupo controle recebeu dieta com 20 por cento de proteínas por 21 dias, sendo entäo submetido a uma anastomose do cólon distal. O outro grupo além de receber a mesma dieta, foi submetido a uma peritonite com fezes humanas. Após 6 horas de evoluçäo da peritonite, os animais foram submetidos a laparotomia, limpeza da cavidade abdominal e anastomose do cólon distal. A dieta a 20 por cento de proteínas foi mantida no pós-operatório dos dois grupos anteriores. O 3º grupo (desnutrido) recebeu no mesmo período anterior (pré e pós-operatório) dieta constituída de caseína e submetido ao mesmo procedimento cirúrgico. Amostras do cólon foram colhidas antes e no 4º, 7º, 14º e 21º dias de pós-operatório para estudo da força de ruptura e da hidroxiprolina tecidual. Dos resultados obtidos verificou-se incidência de 11,7 por cento e 7 por cento de deiscência respectivamente nos grupos peritonite e desnutrido, além de concomitância na diminuiçäo da força de ruptura e da hidroxiprolina tecidual

Fecal peritonitis in the rat: alterations of the distal colon wall: a biomechanical and anatomopathologic study / Peritonite fecal no rato: alteraçöes da parede do colon distal: estudo biomecânico e anatomopatológico

Este trabalho verificou as alteraçöes da parede do cólon distal do rato na vigência de peritonite fecal, induzida por uma suspensäo de fezes humana. As repercussöes da infecçäo peritoneal na parede do cólon distal foram avaliados mediante estudo anatomopatológico, força de ruptura e da hidroxiprolina e proteína tecidual. Os animais foram estudados em 5 momentos, correspondendo a 3, 6, 12, 18 e 24 horas após a induçäo da peritonite. O exame macroscópico e histológico revelou o caráter evolutivo da infecçäo peritoneal, caracterizado por um processo inflamatório exsudativo, que se acentuou no decorrer das 24 horas. A concentraçäo do colágeno, avaliado pela relaçäo hidroxiprolina/proteína tecidual, manteve-se dentro do intervalo de confiança da média dos animais do grupo controle e nos 5 momentos estudados. Após 3 horas de evoluçäo da peritonite a força de ruptura apresentou queda de 20 por cento em relaçäo ao grupo controle, e manteve-se em níveis inferiores ao controle em todos os momentos. Dos parâmetros utilizados, a força de ruptura foi o mais demonstrativo de lesäo da parede do cólon distal pela peritonite fecal

Efeito da peritonite fecal na cicatrizaçäo do cólon distal no rato: avaliaçäo anatomopatológica, estudo da força de ruptura e da hidroxiprolina tecidual / Effect of fecal peritonitis on healing of the distal colon in the rat: anatomopathologic evaluation, study of breaking strength and of tissue hydroxyproline

Força de ruptura, dosagem da concentraçäo de hidroxiprolina e proteína tecidual e estudo tecidual foram efetuados na parede do cólon distal do rato, em animais submetidos a injeçäo intraperitoneal de soro fisiológico (controle) e em animais submetidos à injeçäo intraperitoneal de uma suspensäo de fezes humanas diluídas em soro fisiológico à 10// (peritonite). Após 6 horas da injeçäo intraperitoneal, os animais foram divididos em 6 momentos experimentais, sendo um lote sacrificado imediatamente após o sorteio (M0) e os restantes, após limpeza da cavidade peritoneal, foram submetidos à secçäo do cólon distal, sendo feita reconstruçäo imediata com fio de polipropileno 6-0, com sutura extramucosa em plano único, sendo estes animais sacrificados após 4 (M1), 7 (M2), 10 (M3), 14 (M4) e 21 (M5) dias de pós-operatório. Em M0, constatamos diminuiçäo da força de ruptura nos animais do grupo peritonite. No pós-operatório verificamos a ocorrência de discência da anastomose cólica em 8// dos animais, todos pertencentes ao grupo peritonite. O encontro de intenso processo inflamatório nos animais do grupo peritonite em M1 e M5, leva-nos a concluir que a etiologia das discências intestinais deve-se ao prolongamento da fase latente do processo de cicatrizaçäo induzido pela infecçäo peritoneal

Repercussöes da desnutriçäo protéico-calórica sobre o colágeno, proteína total, RNA, DNA e peso pulmonar de ratas adultas / Effects of protein-caloric restriction on collagen, total protein, RNA, DNA and lung weight of adult female rat lungs

A restriçäo protéico-calórica em ratas adultas, durante 21 dias, acarretou queda significante nos pesos corporal e pulmonar desses animais, sem alterar significantemente o conteúdo de água e de DNA de seus pulmöes. A desnutriçäo protéico-calórica provocou, ainda, reduçäo significante no conteúdo pulmonar de RNA, proteína total e das relaçöes RNA/DNA e proteína total/DNA, indicando uma possível diminuiçäo da sintese protéica e do tamanho das células pulmonares respectivamente. As concentraçöes de RNA e proteína total foram semelhantes enquanto a de DNA foi signifivantemente superior nas ratas desnutridas. A desnutriçäo protéico-calórica näo afetou o conteúdo de hidroxiprolina do pulmäo enquanto ocasionou uma elevaçäo significante nas concentraçöes desse aminoácido, sugerindo a ocorrência de maior deposiçäo de colágeno ou a lentidäo de seu "turnover" em relaçäo aos das demais proteínas desse órgäo

Synergistic effect of cortisol and thyrotrophin releasing hormone on lung maturation in the fetal sheep entails connective tissue maturation

Pressure-volume relationships and collagen and elastin contents were measured in the lungs of fetal sheep infused either with saline (n = 4), thyrotrophin-releasing hormone (TRH; n = 6), cortisol (n = 9) or TRH plus cortisol (n = 10) at 128 days of gestation (term = 149 days) for 7 days. Lung distensibility (V40 = 1.8 +/- 0.1 ml/g wet wt; mean +/- SD) and stability (V5 = 0.6 +/- 0.1) increased along with collagen (C) (10.1 +/- 2.7 micrograms/mg) and elastin (E) contents (128 +/- 35 ng/mg) in the animals infused with TRH plus cortisol and were significantly higher (p < 0.05) than those observed in TRH (V40 0.62 +/- 0.07; V5 0.32 +/- 0.04; C 3.53 +/- 1.3; E 38.2 +/- 8.3), cortisol (V4 0.66 +/- 0.6; V5 0.27 +/- 0.03; C 4.27 +/- 0.8; E 41.02 +/- 12.7) or saline infused fetuses (V40 0.40 +/- 0.1; V5 0.20 +/- 0.06; C 3.28 +/- 0.9; E 31.5 +/- 9.2). Plasma concentrations of prolactin (PRL), triiodothyronine (T3) and cortisol (F) were also higher in the group of fetuses infused with both hormones in comparison with the other groups. In fetuses treated with TRH plus cortisol, PRL (32 +/- 8.3 ng/ml) and T3 (308.3 +/- 36 micrograms/dl) were significantly higher than in those infused with cortisol alone (PRL 3.7 +/- 2.3; T3 128 +/- 30) or with saline (PRL 4.2 +/- 1.6; T3 < 5 micrograms/dl). In the group treated with TRH alone, PRL also increased significantly (37 +/- 6.4), but T3 increased only slightly (18 +/- 3.4).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of dimethoate on collagen metabolism in rats.

The effects of three different doses of dimethoate on the collagen metabolism in the tissues of female albino rats were studied by measuring the specific and total activities of 3H-hydroxyproline in the dermal, gingival and uteral collagen fractions and in the urine. Compared to controls, the total activity of 3H-hydroxyproline in the soluble collagen and in the urine at 12 h after the administration of 3H-proline was significantly lower by 44.45 and 58.12 per cent in the higher dose (2.25 mg/100 g body weight) of dimethoate treated groups respectively. The urinary excretion of hydroxyproline and the total activity of urinary 3H-hydroxyproline measured after 28 days of injection of labelled proline were decreased by 45.56 and 32.68 per cent in higher doses of dimethoate treated animals respectively but the excretions of urinary 3H-hydroxyproline were decreased by 6.36 and 2.88 per cent in lower doses of dimethoate (0.56 mg/100 g body weight) treated animals. The results of the present investigation clearly indicate that the synthesis of collagen is decreased in the higher doses of dimethoate treated animals compared to lower doses of dimethoate treated animals. In addition, the rates of catabolism of both soluble and insoluble collagens were decreased in higher doses of dimethoate treated rats. In concludes that the lower doses of dimethoate (0.56 mg) treated rats were less affected than the higher doses of dimethoate (2.25 mg) treated rats.