Arginine-containing peptides and their influenceon normal hemostatic parameters in rats

Author(s):  
Э.Я. Рогозинская ◽  
М.Е. Григорьева ◽  
Л.А. Ляпина

Введение. В ранних исследованиях была выявлена способность аргининсодержащих пептидов глипролинового ряда в условиях in vitro оказывать антикоагулянтные и суммарные фибринолитические эффекты на плазму крови лабораторных крыс. Цель исследования: изучение действия аргининсодержащих глипролинов HisPheArgTrpProGlyPro (HFRWPGP), ThrLysProArgProGlyPro (TKPRPGP), ArgGluArgProGlyPro (RERPGP) на параметры системы гемостаза крыс в условиях in vivo в норме и сравнительный анализ эффектов исследуемых пептидов с глипролином (PGP). Материалы и методы. В работе использовали пептиды HFRWPGP (АКТГ(69)PGP), TKPRPGP (Селанк), RERPGP и PGP. В опытах 20 белым лабораторным крысам интраназально вводили по 0,02 мл раствора каждого из пептидов в дозе 1 мкг/кг массы тела (3 опытных группы) или 0,85 раствора NaCl (контрольная группа) через каждые 24 ч в течение 7 суток (168 ч). Влияние пептидов на параметры гемостаза исследовали тромбоэластографическим методом, в тестах активированного частичного тромбопластинового времени и агрегации тромбоцитов, а также определяли фибринолитическую активность крови на нестабилизированном фибрине. Результаты. Каждый из исследованных препаратов обнаруживал антикоагулянтную, фибринолитическую, антитромбоцитарную активности. Противосвертывающие эффекты проявлялись через 20 ч после последнего введения и сохранялись на протяжении 168 ч. Наибольшим эффектом обладали пептиды, в состав которых входил аргинин ArgGluArgProGlyPro и Селанк. Заключение. Аминокислота аргинин в составе олигопептидов глипролинового ряда способствует усилению активации противосвертывающей системы. Introduction. Early in vitro studies revealed anticoagulant and fibrinolytic effects of argininecontaining glyprolins on plasma in rats. Aim: to study the effects of argininecontaining glyprolines HisPheArgTrpProGlyPro (HFRWPGP), ThrLysProArgProGlyPro (TKPRPGP), ArgGluArgProGlyPro (RERPGP) on rats hemostasis in vivo in normal conditions and to compare the effects of test peptides with glyproline (PGP). Materials and methods. The following peptides were used: HFRWPGP (ACTH(69)PGP), TKPRPGP (Selank), RERPGP and PGP. In experiments 20 white rats were intranasally injected with 0.02 ml of each peptide solution in a dose of 1 g/kg body weight (3 experimental groups) or 0.85 NaCl solution (control group) every 24 hours for 7 days (168 hours). The effects of peptides on hemostatic parameters were investigated by thromboelastographic method, by activated partial thromboplastin time and platelet aggregation, also fibrinolytic blood activity on nonstabilized fibrin was determined. Results. All tested peptides showed anticoagulant, fibrinolytic, antiplatelet activity. Anticoagulant effects manifested 20 hours after the last injection and persisted for 168 hours. Argininecontaining ArgGluArgProGlyPro and Selank showed the greatest effect. Conclusion. Arginine as a part of argininecontaining glyprolines intensified the activation of anticoagulation system.

2019 ◽  
Vol 18 (3) ◽  
pp. 574-576
Author(s):  
VV Bykov ◽  
V Yu Serebrov ◽  
VV Udut ◽  
EV Udut ◽  
VP Fisenko

Objective. Specific activity of an antiplatelet drug of indolinone series (codenamed DI) was studied in vitro in a model of ADP-induced platelet aggregation in vitro and in vivo in a model of streptozotocininduced diabetes mellitus in rats. Material and Methods. Acetylsalicylic acid and dipyridamole were used as reference drugs. In vitro tests have demonstrated that DI exhibits antiplatelet activity in a wide range of concentrations (0,75×10-6 – 1.5×10-5 М, р<0,05), being comparable to acetylsalicylic acid and dipyridamole. In vivo tests have demonstrated dose-dependent antiplatelet activity of DI in doses of 2,5 – 20 mg/kg (21-14 %). Results and Discussion.Increasing the dose of DI above 10 mg/kg doesn’t increase its antiplatelet activity. After multiple oral administration to rats with streptozotocin-induced diabetes mellitus in 10 mg/kg dose, DI has exhibited antiplatelet activity, reducing the platelet aggregation rate to that of the control group (р<0,05). Conclusion. Thus, DI isapromisingcompound for furtherdevelopmentof an antiplatelet drug with new mechanism of action Bangladesh Journal of Medical Science Vol.18(3) 2019 p.574-576


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 331
Author(s):  
Jung-Yun Lee ◽  
Tae Yang Kim ◽  
Hanna Kang ◽  
Jungbae Oh ◽  
Joo Woong Park ◽  
...  

Excess body weight is a major risk factor for type 2 diabetes (T2D) and associated metabolic complications, and weight loss has been shown to improve glycemic control and decrease morbidity and mortality in T2D patients. Weight-loss strategies using dietary interventions produce a significant decrease in diabetes-related metabolic disturbance. We have previously reported that the supplementation of low molecular chitosan oligosaccharide (GO2KA1) significantly inhibited blood glucose levels in both animals and humans. However, the effect of GO2KA1 on obesity still remains unclear. The aim of the study was to evaluate the anti-obesity effect of GO2KA1 on lipid accumulation and adipogenic gene expression using 3T3-L1 adipocytes in vitro and plasma lipid profiles using a Sprague-Dawley (SD) rat model. Murine 3T3-L1 preadipocytes were stimulated to differentiate under the adipogenic stimulation in the presence and absence of varying concentrations of GO2KA1. Adipocyte differentiation was confirmed by Oil Red O staining of lipids and the expression of adipogenic gene expression. Compared to control group, the cells treated with GO2KA1 significantly decreased in intracellular lipid accumulation with concomitant decreases in the expression of key transcription factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (CEBP/α). Consistently, the mRNA expression of downstream adipogenic target genes such as fatty acid binding protein 4 (FABP4), fatty acid synthase (FAS), were significantly lower in the GO2KA1-treated group than in the control group. In vivo, male SD rats were fed a high fat diet (HFD) for 6 weeks to induced obesity, followed by oral administration of GO2KA1 at 0.1 g/kg/body weight or vehicle control in HFD. We assessed body weight, food intake, plasma lipids, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) for liver function, and serum level of adiponectin, a marker for obesity-mediated metabolic syndrome. Compared to control group GO2KA1 significantly suppressed body weight gain (185.8 ± 8.8 g vs. 211.6 ± 20.1 g, p < 0.05) with no significant difference in food intake. The serum total cholesterol, triglyceride, and low-density lipoprotein (LDL) levels were significantly lower in the GO2KA1-treated group than in the control group, whereas the high-density lipoprotein (HDL) level was higher in the GO2KA1 group. The GO2KA1-treated group also showed a significant reduction in ALT and AST levels compared to the control. Moreover, serum adiponectin levels were significantly 1.5-folder higher than the control group. These in vivo and in vitro findings suggest that dietary supplementation of GO2KA1 may prevent diet-induced weight gain and the anti-obesity effect is mediated in part by inhibiting adipogenesis and increasing adiponectin level.


2004 ◽  
Vol 92 (07) ◽  
pp. 89-96 ◽  
Author(s):  
David Payne ◽  
Chris Jones ◽  
Paul Hayes ◽  
Sally Webster ◽  
A. Naylor ◽  
...  

SummaryThe majority of patients who suffer peri-operative thromboembolic complication while undergoing vascular procedures do so despite taking aspirin. This study examined the antiplatelet effect of aspirin during surgery in patients undergoing carotid endarterectomy (CEA). Fifty patients undergoing CEA were standardised to 150 mg aspirin daily for ≥2 weeks. Platelet aggregation in response to arachidonic acid (AA) was measured in platelet rich plasma prepared from blood taken prior to, during, and at the end of surgery. Spontaneous platelet aggregation was also studied, as was the role of physiological agonists (ADP, collagen, thrombin, and epinephrine) in mediating the in vivo and in vitro responses to AA. Eighteen patients undergoing leg angioplasty, also on 150 mg aspirin, without general anaesthesia, served as a control group. In the CEA patients aggregation induced by AA (5 mM) increased significantly from 7.6 ± 5.5% pre-surgery to 50.8 ± 29.5% at the end of surgery (p <0.0001). Aggregation to AA was even greater in samples taken mid-surgery from a sub-set of patients (73.8 ± 7.2%; p = 0.0001), but fell to 45.9 ± 7.4% by the end of surgery. The increased aggregation in response to AA was not due to intra-operative release of physiological platelet agonists since addition of agents that block/neutralise the effects of ADP (apyrase; 4 µg/ml), thrombin (hirudin; 10 units/ml), or epinephrine (yohimbine; 10 µM/l) to the samples taken at the end of surgery did not block the increased aggregation.The patients undergoing angioplasty also showed a significant rise in the response to AA (5 mM), from 5.6 ± 5.5% pre-angioplasty to 32.4 ± 24.9% at the end of the procedure (p <0.0001), which fell significantly to 11.0 ± 8.1% 4 hours later. The antiplatelet activity of aspirin, mediated by blockade of platelet arachidonic acid metabolism, diminished significantly during surgery, but was partially restored by the end of the procedure without additional aspirin treatment.This rapidly inducible and transient effect may explain why some patients undergoing cardiovascular surgery remain at risk of peri-operative stroke and myocardial infarction.


2007 ◽  
Vol 2 (1) ◽  
pp. 22
Author(s):  
Enok Sobariah ◽  
Ali Khomsan ◽  
Ingrid S. Surono

<p class="MsoNormal" style="margin: 0cm 12.45pt 6pt 17.85pt; text-align: justify;"><span style="font-size: 10pt;" lang="en-us" xml:lang="en-us">The aim of this study were  to identify the in-vitro tolerance of pro-biotic bacteria to acid and bile salt condition; and  to prove a hypothesis that the supplementation of oxygenated water has a positive effect on the body weight of rat and on viability of pro-biotic bacteria.  The first study was carried out at PAU Laboratory of Bogor Agricultural University, while the second study was conducted at Department of Community Nutrition of Bogor Agricultural University and Microbiology Laboratory of Indonesia Institute of Technology. Forty five rats aged 6 weeks were divided into three groups, i.e., control group without probiotic (a0), Lactobacillus casei Shirota (a1), and Lactobacillus IS-7257 (a2).  Each group (consisting of 5 rats each) has three different treatments, namely, control without oxygenated water (b0), 50 ppm oxygenated water (b2), and 80 ppm oxygenated water (b2). Oxygenated water was administered to the rats twice a day in the morning (3.25 ml) and afternoon (3.00 ml). Observation was carried out on the body  weight of the rats, fecal lactic acid bacteria, coliform, and anaerob bacteria by plate counting, for 4 periods, i.e, prior to the treatment (C0), after three-day treatment (C1), after seven-day treatment (C2), and on the 10<sup>th</sup> day treatment or three days after washed out period. The results indicated that probiotic bacteria are resistant to acid and bile acid condition. Oxygen concentration in water has a significant positive influence on the body weight of rats towards viability of probiotic bacteria (p-level &lt; 0.05).  The supplementation of  oxygenated water 50 ppm significantly increase the population of viable fecal lactic acid bacteria in L. casei Shirota and Lactobacillus IS-7257 groups after 3 and 7 days of treatment.  Lactobacillus IS-7257 gave better response than L. casei Shirota. The supplementation of oxygenated water 80 ppm significantly reduces the fecal coliform in-vivo in both L. casei Shirota and Lactobacillus IS-7257 groups (p-level &lt; 0.05).</span></p>


2018 ◽  
Vol 39 (3) ◽  
pp. 269-284
Author(s):  
G.D. Chechet ◽  
J Yahaya ◽  
A.J. Nok

Animal African trypanosomiasis (AAT) also known as Nagana is a resurgent disease in Africa. Medicinal plants are being used in less developed countries for the treatment of various diseases including trypanosomiasis, due to the high cost of currently available drugs. Most of these plants have been useful sources of treatment of various diseases based on information obtained from folk medicine but have not been scientifically certified. Here, we investigated the in vitro and in vivo anti-trypanosomal potentials of the methanol extract of Aformorsia laxiflora and Khaya senegalensis against T. b. brucei. Phytochemical screening as well as LD50 of the plant extracts was carried out following standard procedures. Parasitemia was monitored daily while Packed Cell Volume was determined at three time points (days 1, 4 and 7) during the course of the infection. The phytochemical analysis showed the presence of saponins, alkaloids, flavonoids, antraquinones, resins and tanins. However, steriods/terpenoids were absent in K. senegalensis but present in A. laxiflora. The toxicity of methanol extract of both A. laxiflora and K. senegalensis was above 5000mg/kg body weight. Methanol extracts of A. laxiflora (leaves) and K. senegalensis (stem bark) showed promising trypanocidal potential in vitro against T. b. brucei at concentrations of 10, 15, 25mg/ml and 40 and 20mg/ml respectively. At these concentrations, both extracts immobilized the parasites within 55mins post-incubation. In general, A. laxiflora leaf extract demonstrated prophylactic activity against T. b. brucei in vivo at a dose of 500mg/Kg body weight particularly in group C animals where a delayed pre-patent period (6 days post-infection), extended survival (14 days post-infection) and significant (P<0.05) reduction in the parasite burden confirmed by an absence of anemia (PCV 47.00±0.8 %) was observed when compared to the infected untreated control group. K. senegalensis extract on the other hand did not show anti-trypanosomal activity in the treated groups (1, 2, and 3). Based on these observations, it was therefore deduced that the methanol extract of leaves of A. laxiflora possessed the ability to ameliorate the burden of the disease and could be a plausible candidate for drug development against the disease.Keywords: Trypanosoma brucei brucei, Afromosia laxiflora, Khaya senegalensis, anti-trypanosomal, in vitro, in vivo


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Silvia I García ◽  
Ludmila S Peres Diaz ◽  
Maia Aisicovich ◽  
Mariano L Schuman ◽  
María S Landa

Cardiac TRH (cTRH) is overexpressed in the hypertrophied ventricle (LV) of the SHR. Additionally in vivo siRNA-TRH treatment induced downregulation of LV-TRH preventing cardiac hypertrophy and fibrosis demonstrating that TRH is involved in hypertrophic and fibrotic processes. Moreover, in a normal heart, the increase of LV TRH expression alone could induce structural changes where fibrosis and hypertrophy could be involved, independently of any other system alterations. Is well-known the cardiac hypertrophy/ fibrotic effects induced by AII, raising the question of whether specific LV cTRH inhibition might attenuates AII induced cardiac hypertrophy and fibrosis in mice. We challenged C57 mice with AII (osmotic pumps,14 days; 2 mg/kg) to induce cardiac hypertrophy vs saline. Groups were divided and , simultaneously to pump surgery, injected intracardiac with siRNA-TRH and siRNA-Con as its control. Body weight, water consume and SABP were measured daily. As expected, AII significantly increased SABP (p<0.05) in both groups treated , although cardiac hypertrophy (heart weight/body weight) was only evident in the group with the cardiac TRH system undamaged, suggesting that the cardiac TRH system function as a necessary mediator of the AII-induced hypertrophic effect. As hypothesized, we found an AII-induced increase of TRH (p<0.05) gene expression (real-t PCR) confirmed by immunofluorescence that was not observed in the group AII+siRNA-TRH demonstrating the specific siRNA treatment efficiency. Furthermore, AII significantly increase (p<0.05) BNP (hypertrophic marker), III collagen and TGFB (fibrosis markers) expressions only in the group with AII with the cardiac TRH system intact. On the contrary, the group with AII and the cTRH system inhibited, shows genes expressions similar to the saline control group. We confirmed these results by immunofluorescence. Similar fibrotic results were observed with NIH3T3 cell culture where we demonstrated that AII induced TRH gene expression (p<0.05) and its inhibition impedes AII-induced increase of TGFB and III/I collagens expressions telling us about the role of the cTRH in the AII fibrosis effects. Our results point out that the cardiac TRH is involved in the AII-induced hypertrophic and fibrotic effects.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1558-1558 ◽  
Author(s):  
Shouyun Li ◽  
Shuang Liu ◽  
Shuying Chen ◽  
Yirui Chen ◽  
Ying Wang ◽  
...  

Abstract Introduction: TBLR1-RARα is the tenth fusion gene of acute promyelocytic leukemia (APL) first identified in a rare case of APL with t(3;17)(q26;q21) chromosomal translocation in our previous study. The characteristics of its basic structure and functions had been clarified in our previous study. In this study, we successfully established a novel TBLR1-RARα leukemia mouse model (TR mouse) which fully recapitulated the most relevant features of human APLs. The therapeutic effects of retinoic acid (ATRA), arsenic trioxide (As2O3), cytarabine (Ara-C) and histone deacetylase inhibitors (HDACi) on TR mice were examined. The differentially expressed genes (DEGs) between TR mice and normal mice were compared to explore the possible mechanisms and better therapeutic targets for this kind of APL. Methods: pMSCV-TBLR1-RARα-Flag-IRES-GFP (MSCV-TR) and pMSCV-IRES-GFP (vehicle) retroviral plasmids were constructed and transfected 293T packaging cells to produce retroviruses. Lin- cells from C57BL/6 mice bone marrow were purified and infected with MSCV-TR and vehicle retroviral supernatant. For in vitro assay, the GFP+ lin- cells sorted and incubated with or without different concentrations of ATRA were analyzed for the differentiation and proliferation capacity by cell morphology, myeloid markers (CD11b and GR-1) and colony formation assay. For the in vivo experiment, GFP+ lin- cells transfected with indicated retroviral vectors were injected intravenously to lethally irradiated C57BL/6 mice to establish an APL mouse model. Cell surface markers were analyzed by flow cytometry. In treatment assays, GFP+ spleen cells from TR leukemia mice were injected intravenously into recipient mice. The mice were randomly separated into groups and received different treatment with ATRA, As2O3, As2O3 in combination with ATRA, Ara-C, Ara-C in combination with ATRA, chidamide and NL101, respectively. The percentage of GFP+ cells in peripheral blood and body weight were measured dynamically. The survival time of every group was recorded and compared. RNA-seq assay was used to identify DEGs between TR mice and normal mice. Results: In vitro assays indicated that TBLR1-RARα could either block the differentiation of HSCs at a relatively early stage or enhanced the clonogenic potential of cells. The TBLR1-RARα leukemia mouse model was successfully established. During the ten-month observational period, 3 out of 15 mice transplanted with TBLR1-RARα expressing cells developed an APL-like disease. Development of leukemia was not observed in any of the mice in control group. All the leukemia mice had a body weight loss as well as splenomegaly and hepatomegaly. The phenotype analysis revealed that the progenitor markers Sca-1, CD34 and C-kit were positive, the myeloid lineage markers Gr-1 and CD11b were also positive, erythroid lineage marker Ter119 was weekly positive, but the lymphatic lineage marker B220, CD3,CD4 and CD8 were all negative. TR mice treated with 1.5-2.5 mg/kg ATRA alone or together with 2.0 mg/kg As2O3 didn't survive longer than that of control group, although in vitro differentiation experiment showed that the leukemia cells were sensitive to ATRA. Leukemic mice receiving Ara-C treatment had a much longer survive time. Surprisingly, HDAC inhibitors (12.5 and 25 mg/kg chidamide and 30 mg/kg NL-101) could significantly prolong the survival time of TR mice. Thousands of DEGs had been identified between TR mice and wild type mice, which were widely involved in multiple pathways and participated in various biological functions. Conclusion: The TBLR1-RARα leukemia mouse model was successfully established for the first time, and its main characteristics were clarified. Although the leukemia cells were sensitive to ATRA in vitro, TR mice didn't benefit from ATRA or As2O3 treatment in vivo. Besides Ara-C, HDAC inhibitors, such as chidamide and NL-101 exhibited potency therapeutic values for TR mice, which provided a new strategy for this kind of refractory APL. What' more, lots of genes that might be related with the process of leukemogenesis and new therapeutic targets for TR leukemia were identified. This model would serve as a versatile tool to study the mechanisms of leukemogenesis and help to design better strategies for APLs in further studies. Disclosures No relevant conflicts of interest to declare.


1987 ◽  
Vol 65 (5) ◽  
pp. 1201-1205 ◽  
Author(s):  
Bodil Korsgaard

The ability of yolk-sac embryos of the blenny Zoarces viviparus (L.) to assimilate and metabolize exogenous glucose was investigated by in vivo and in vitro experiments. The investigations in vivo (experiment I) were performed by simultaneously injecting 14C-labelled glucose (30 μL (5 μCi)/100 g body weight) and unlabelled carrier glucose (100 mg/100 g body weight) into the ovary (loaded group). Controls received only 14C-labelled glucose (nonloaded group). The shape of the disappearance curve for the tracer glucose in the glucose-loaded group was similar to that for carrier glucose, with a gradual decrease during the first 9 h postinjection. Half-lives were calculated to be 5.17 h for tracer glucose and 5.41 h for carrier glucose in the loaded group. Both tracer and carrier glucose levels returned to control levels after 24 h in the loaded group. Accumulation of tracer glucose was significantly higher in yolk-sac embryos from the nonloaded control group compared with embryos from the loaded group. Tracer accumulation in maternal liver and kidney was low and showed an opposite pattern to accumulation in the embryos, with more tracer accumulated in the maternal liver and kidney from the loaded group compared with controls. After intraovarian preincubation with [14C]glucose, release of 14CO2 and DO14C (dissolved organic carbon) from assimilated tracers in the embryos in vitro was low. In another experiment (experiment II) the embryos were dissected out of the ovary of untreated females and incubated in vitro with [14C]glucose. The embryos assimilated the labelled glucose, and uptake rates were correlated with the ambient concentration of carrier glucose. Release from embryos into the medium of 14CO2 and DO14C from assimilated tracer glucose was at the same low level as after intraovarian preincubation with [14C]glucose in experiment I. In combination, the results show that as early as their yolk-sac period, embryos from Zoarces viviparus have the capacity for assimilating and metabolizing glucose from naturally occurring concentrations in the ovarian fluid in vivo or from media in vitro.


2007 ◽  
Vol 97 (3) ◽  
pp. 458-463 ◽  
Author(s):  
Cristina Luceri ◽  
Lucia Giannini ◽  
Maura Lodovici ◽  
Emilia Antonucci ◽  
Rosanna Abbate ◽  
...  

p-Coumaric acid (3-(4-hydroxyphenyl)-2-propenoic acid; 4CA), is a ubiquitous plant metabolite with antioxidant and anti-inflammatory properties. The antiplatelet activity of this compound was analysed both ex vivo and in vitro. 4-CA, administered to rabbits for 2 weeks at the dose of 5 mg/kg, mixed with food, inhibited ADP-induced platelet aggregation without affecting blood coagulation. This effect was associated with a marked increase in plasma antioxidant activity, measured as ferric reducing ability of plasma, and with the reduction of thromboxane B2 production. The antiplatelet effect was confirmed by in vitro experiments on human blood: 4CA (500 μm and 1 mm) reduced ADP-induced platelet aggregation (55·2 (se 4·01) % and 35·6 (se 2·35) % relative to basal level, respectively). 4CA was able to modify platelet function, measured with PFA-100™, a shear-inducing device that simulates primary haemostasis. 4CA interfered also with arachidonic acid cascade, reducing thromboxane B2 production and lipopolysaccharide-induced prostaglandin E2 generation (ic50 371 and 126 μm, respectively). The data show that 4CA is an antioxidant compound with good antiplatelet activity at doses that can be obtained with dietary intervention, suggesting possible applications for primary prevention of vascular disease.


2003 ◽  
Vol 23 (3) ◽  
pp. 228-236 ◽  
Author(s):  
Cheng-Chung Fang ◽  
Ming-Nan Lai ◽  
Chiang-Ting Chien ◽  
Kuan-Yu Hung ◽  
Chien-Chen Tsai ◽  
...  

♦ Background Peritoneal fibrosis is a long-term complication following continuous ambulatory peritoneal dialysis (CAPD). Peritoneal fibroblasts may play an important role in peritoneal fibrosis. Up to now, the treatment of peritoneal fibrosis in patients with CAPD remains unsatisfactory. Pentoxifylline (PTX) is a xanthine derivative and is used in the treatment of peripheral vascular and cerebrovascular diseases. Several studies have demonstrated that PTX can ameliorate fibrosis of the skin, liver, and kidney. ♦ Objective To investigate the effect of PTX on in vitro growth and collagen synthesis of human peritoneal fibroblasts (HPFBs), and to evaluate the effects of PTX on silica-induced peritoneal fibrosis in vivo. ♦ Design and Measurements In the in vitro study, HPFBs were cultured from human omentum. The effect of PTX on the growth of serum-stimulated HPFBs was evaluated by MTT assay. The effect of PTX on the collagen synthesis of HPFB was measured by [3H]-proline incorporation. Expression of type I and type III collagen mRNA was evaluated by Northern blotting. The effects of PTX on matrix metalloproteinase (MMP) activity and cAMP level in HPFBs were measured by immunoassays. In the in vivo study, Wistar rats were randomly divided into five groups. All rats received intraperitoneal (IP) injection of silica suspension (250 mg/100 g body weight) on day 0. The rats of group 1 (control group) were injected with vehicle IP every day for 14 days. The rats of groups 2, 3, and 4 were injected with PTX (4 mg/100 g body weight) IP every day for 3, 7, and 14 days, respectively. The rats in group 5 received an intravenous infusion of PTX (8 mg/100 g body weight) every day for 7 days. On the 15th day after silica injection, all rats were sacrificed. Their parietal and visceral peritoneums were removed and processed for pathology, and the severity of fibrosis was measured and scored. ♦ Results: In vitro, PTX inhibited serum-stimulated HPFB growth (maximum was 93% at 1 mg PTX/mL) in a dose-dependent manner. Collagen synthesis by HPFB was reduced (47% at 1 mg PTX/mL), and collagen I and III mRNA expression in HPFBs was suppressed by PTX. The PTX did not affect the MMP (including MMP-1, MMP-8, and MMP-13) activities of HPFBs. The mechanism of PTX was through increasing cAMP by its phosphodiesterase inhibiting activity. In vivo, the severity of fibrosis was significantly reduced in groups 4 and 5 compared to group 1 ( p < 0.05). ♦ Conclusion These results suggest that PTX can inhibit growth of and collagen synthesis by HPFBs in vitro. The fibrosis derived from silica-induced peritonitis in vivo was also ameliorated by PTX. Therefore, pentoxifylline may have the potential to be used to treat peritoneal fibrosis in patients on CAPD.


Sign in / Sign up

Export Citation Format

Share Document