RESUMO
AIMS OF THE STUDY: Royal jelly (RJ) is one of the most widely used drugs in traditional medicine. One of its important applications is the repair of skin damage, although the path of its mechanism is still unknown. Platelet-derived growth factor-beta (PDGF-beta) is one of the important factors in wound healing and it has been observed that PDGF-ß expression decreases with increasing age. In this study, for the first time, the effect of RJ on skin wounds has been investigated through the expression of PDGF-ß and tissue studies. MATERIALS AND METHODS: 25 small laboratory male BALB/c mice were selected randomly and after creating a 5 mm wound on the back of their neck, they were treated with doses of 2.5, 10, and 40 mg/kg body weight, After sampling from the healed wound in 9th day, histopathological studies and the expression of PDGF-ß gene were performed by Real-time PCR method. RESULTS: The findings of the present study showed that royal jelly caused a significant increase in PDGF-ß (10.99 times) compared to the healthy group. Also, royal jelly increased the formation of covering tissue or epithelium, the synthesis of collagen, the presence of inflammatory cells, and the formation of new blood vessels. CONCLUSION: The oral treatment of royal jelly is probably effective in skin wound healing by changing the expression of PDGF-ß.
Assuntos
Fator de Crescimento Derivado de Plaquetas , Cicatrização , Camundongos , Masculino , Animais , Fator de Crescimento Derivado de Plaquetas/farmacologia , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Derivado de Plaquetas/genética , Colágeno/farmacologia , Ácidos Graxos/farmacologia , Ácidos Graxos/uso terapêuticoRESUMO
Liver fibrosis is an important process that occurs in most types of chronic liver diseases and often results in the end stage of liver diseases, such as cirrhosis, portal hypertension, and hepatocellular carcinoma. Sorafenib, a multiple tyrosine kinase inhibitor, has been shown to inhibit liver fibrosis in multiple experimental fibrosis mouse and rat models. The aim of this study was to test the therapeutic effect of sorafenib on liver fibrosis induced by infection with a parasite, Schistosoma japonicum, in mice. Mice were percutaneously infected through the abdomen with Schistosoma cercariae to develop a schistosomula liver fibrosis model. Eight weeks after infection, infected mice were treated with the anti-parasitic agent praziquantel for 2 days and sorafenib for 2 weeks. Hepatic histopathological changes were assessed using hematoxylin and eosin (HE) and Masson's trichome staining. The hepatic expression levels of collagen I, collagen III, alpha-smooth muscle actin (α-SMA), platelet-derived growth factor (PDGF), and PDGF receptor-beta (PDGFR-ß) were analyzed by immunohistochemistry and western blot. Praziquantel administration alone but not sorafenib reduced liver fibrosis, and the combination of praziquantel and sorafenib significantly attenuated liver fibrosis in S. japonicum-infected mice. Moreover, sorafenib plus praziquantel markedly decreased the hepatic deposition of collagen and expression of fibrogenic genes in these mice. In conclusion, the use of sorafenib following praziquantel treatment may represent a potential therapeutic strategy for liver fibrosis induced by S. japonicum in patients.
Assuntos
Cirrose Hepática/tratamento farmacológico , Fígado/patologia , Niacinamida/análogos & derivados , Compostos de Fenilureia/uso terapêutico , Praziquantel/uso terapêutico , Schistosoma japonicum/efeitos dos fármacos , Esquistossomose Japônica/tratamento farmacológico , Actinas/análise , Actinas/metabolismo , Animais , Colágeno Tipo I/análise , Colágeno Tipo I/metabolismo , Colágeno Tipo III/análise , Colágeno Tipo III/metabolismo , Feminino , Fígado/parasitologia , Cirrose Hepática/parasitologia , Cirrose Hepática/patologia , Camundongos , Camundongos Endogâmicos BALB C , Niacinamida/uso terapêutico , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/análise , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Schistosoma japonicum/metabolismo , Esquistossomose Japônica/parasitologia , SorafenibeRESUMO
OBJECTIVE: To study the effect of oral administration of dimethyl dimethoxy biphenyl dicarboxylate (DDB) on adjusting angiogeneic/inflammatory mediators and ameliorating the pathology of bones in rats with collagen-induced arthritis (CIA). METHODS: Wistar rat model of CIA was set up using bovine collagen type II. Fifty rats were divided into five groups randomly: normal, CIA model, DDB treatment, methotrexate (MTX) treatment, and combined DDB+MTX treatment. Ankle joints of rats were imaged with digital X-ray machine to show the destruction of joints. Fore and hind paw and knee joints were removed above the ankle joint then processed for haematoxylin and eosin staining. Plasma levels of vascular endothelial growth factor (VEGF), platelet derived growth factor, interleukin-8 (IL-8), IL-4, tumor necrosis factor α (TNF-α), and cyclooxygenase-2 (COX-2) were quantified by enzyme-linked immunosorbent assay. Nitric oxide levels were detected by Griess reagent. RESULTS: Compared with the CIA model group, a remarkable reduction in various angiogenic (VEGF and IL-8) and inflammatory mediators (TNF-α, IL-4 and COX-2) after treatment with DDB either alone or combined with MTX P<0.05 or P<0.01). Histopathological and X-ray findings were confirmatory to the observed DDB anti-arthritic effect. The DDB-treated group showed amelioration in signs of arthritis which appeared essentially similar to normal. CONCLUSION: Our data shed light on the therapeutic efficacy of DDB in experimental rheumatoid arthritis (RA) compared with a choice drug (MTX) and it may be offered as a second-line drug in the treatment of RA.
Assuntos
Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Dioxóis/uso terapêutico , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/diagnóstico por imagem , Artrite Experimental/patologia , Artrite Reumatoide/diagnóstico por imagem , Artrite Reumatoide/patologia , Colágeno , Ciclo-Oxigenase 2/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Interleucina-4/sangue , Interleucina-8/sangue , Metotrexato/uso terapêutico , Óxido Nítrico/biossíntese , Fator de Crescimento Derivado de Plaquetas/análise , Radiografia , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/sangue , Fator A de Crescimento do Endotélio Vascular/sangueRESUMO
OBJECTIVE: Postoperative adhesions are a serious problem. In this study, we aimed to observe the effects of sorafenib in postoperative adhesions and, to examine the effects of sorafenib on tissue levels of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). MATERIAL AND METHODS: Twenty female Wistar albino rats were randomized into two equal groups; sorafenib group (sorafenib treated) and control group; then all rats underwent laparotomy. Adhesions were developed by scalping on the anti-mesenteric surfaces of the right uterine horns. After 14 days, adhesions were investigated by using macroscopic, histopathological and immunohistochemical (for VEGF and PDGF) methods. RESULTS: The sorafenib group had lower scores of total adhesions [1 (0-2.5) vs 1.5 (1-4); p: 0.037], staining of VEGF [1 (0-1) vs 1 (1-3); p: 0.029] and PDGF [1 (0-2) vs 2 (1-3); p: 0.006], and vascular proliferation [1 (0-2) vs 2 (1-3); p: 0.038] than the control group. CONCLUSION: The findings of the present study show that sorafenib, a tyrosine kinase inhibitor, significantly reduced postoperative adhesion formation. This effect may be explained by inhibition of VEGF, PDGF, and thus vascular proliferation.
Assuntos
Benzenossulfonatos/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêutico , Aderências Teciduais/prevenção & controle , Doenças Uterinas/prevenção & controle , Animais , Modelos Animais de Doenças , Feminino , Imuno-Histoquímica , Niacinamida/análogos & derivados , Compostos de Fenilureia , Fator de Crescimento Derivado de Plaquetas/análise , Proteínas Tirosina Quinases/antagonistas & inibidores , Ratos , Ratos Wistar , Sorafenibe , Aderências Teciduais/patologia , Doenças Uterinas/patologia , Útero/química , Útero/patologia , Fator A de Crescimento do Endotélio Vascular/análiseRESUMO
Visible and infrared (IR) irradiation of laser and non-laser sources has a pronounced wound-healing effect promoting tissue repair without hyperproduction of connective tissue elements. This effect develops as a consequence of local and systemic light effects, but many aspects of their mechanism have been yet unclear. In the present work, we have shown that in 0.5 h after irradiation of a small area of the volunteers' body surface with polychromatic visible + IR light (400-3400 nm, 95% polarization, 12 J/cm2) the amounts of PDGF and TGF-beta 1 in the blood serum increase, on average, by 20 and 43%, respectively. This effect is preserved for at least 24 h to be recorded only in volunteers with the initially normal and decreased levels of the growth factors; the initially elevated content of PDGF-AB decreases. Addition of such a plasma (2.5%) to the nutrient medium of primary cultures of human embryonal fibroblasts stimulates cell proliferation, on average, by 10 and 17%, but only in the case if the initial growth-promoting (GP) blood activity was low. Similar changes occur in parallel experiments following irradiation of blood samples of the same volunteers in vitro, as well as at mixing irradiated and non-irradiated autologous blood at the ratio 1:10 (v/v), i.e. at modeling a situation in the vascular bed, when the transcutaneously photomodified blood contacts with the rest of its volume. Similar changes in the blood GP activity under conditions in vitro were recorded as well after 4-9 daily phototherapy sessions. This allows us to suggest that changes in GP activity of circulating blood of the irradiated volunteers may be, to a large extent, the consequence of effect exerted on the blood by small amounts of transcutaneously photomodified blood. The obtained results are discussed in terms of light effect on wound healing and scar tissue formation, with regard to the authors' previous data on much higher GP of the irradiated blood in respect to keratinocytes, the fast decrease in proinflammatory cytokine levels, and the increase in IFN-gamma content.
Assuntos
Sangue/efeitos da radiação , Fibroblastos/citologia , Raios Infravermelhos , Adolescente , Adulto , Idoso , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Mamíferos , Fibroblastos/efeitos dos fármacos , Substâncias de Crescimento/sangue , Substâncias de Crescimento/farmacologia , Humanos , Pessoa de Meia-Idade , Fator de Crescimento Derivado de Plaquetas/análise , Fatores de Tempo , Fator de Crescimento Transformador beta/análiseRESUMO
An important reason to improve methods for isolating platelet-rich plasma (PRP) is the potential use of autogenous platelet growth factors. In addition to the Curasan PRP kit (Curasan, Kleinostheim, Germany) and the platelet concentrated collection system (PCCSTM) system, two new methods for the preparation of PRP by the surgeon are now available. This study compared the suitability of these new methods for the preparation of PRP. Whole blood was drawn from 54 healthy donors (33 men and 21 women) aged 23-79 years (38.0 +/- 17.7 years). PRP was prepared from each donor's blood using both the Smart PRePTM system (Harvest Technologies Corporation, Munich, Germany) and the Friadent-Schütze method (PRP kit; Friadent-Schütze, Vienna, Austria). The platelet count in donor whole blood was 276 810 +/- 59 440 /microl. Platelet counts differed significantly between the Smart PRP preparation (1227 890 +/- 312 440 platelets/microl) and the Friadent-Schütze PRP preparation (1440 500 +/- 501 700 platelets/microl) (sign test, P < 0.001). The Smart PRePTM system had a significantly higher collection efficiency (63.4 +/- 7.9%) than the Friadent-Schütze kit (49.6 +/- 13.6%) (sign test, P < 0.001). The leukocyte contents in the two platelet concentrates were similar (Smart PRePTM, 19 261 +/- 8082 platelets/microl; Friadent-Schütze, 21 691 +/- 16 430). Transforming growth factor (TGF)-beta1 and platelet-derived growth factor (PDGF)-AB were higher in the Friadent-Schütze PRP (TGF-beta1, 196.8 +/- 109.6 ng/ml; PDGF-AB, 251.6 +/- 115.4 ng/ml) than in the Smart PRePTM (TGF-beta1, 77.2 +/- 54.8 ng/ml; PDGF-AB, 208 +/- 85.2 ng/ml). The sign test indicated significant differences between the two methods in the concentrations of TGF-beta1 (P < 0.001) and PDGF-AB (P < 0.01). Insulin-like growth factor (IGF)-1 levels in the two PRP preparations were similar (Friadent-Schütze PRP, 72.8 +/- 22.3 ng/ml; Smart PRePTM, 91.4 +/- 21.3 ng/ml). The Smart PRePTM system was superior with respect to ease of handling and preparation time. It also had a significantly higher platelet collection efficiency than the Friadent-Schütze PRePTM kit. The Friadent-Schütze PRP kit offers a slight advantage in the resulting PRP platelet concentration. However, this is easily compensated for in the Smart PRePTM system by reducing the volume of the resulting PRP.
Assuntos
Transfusão de Sangue Autóloga/métodos , Transfusão de Plaquetas/métodos , Adulto , Idoso , Plaquetas/fisiologia , Transfusão de Sangue Autóloga/instrumentação , Feminino , Humanos , Fator de Crescimento Insulin-Like I/análise , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Transfusão de Plaquetas/instrumentação , Fator de Crescimento Derivado de Plaquetas/análise , Plaquetoferese/instrumentação , Plaquetoferese/métodos , Estatísticas não Paramétricas , Fator de Crescimento Transformador beta/análise , Fator de Crescimento Transformador beta1RESUMO
The aim of the present study was to compare three different systems for preparing platelet concentrates: two commercially available bed-side techniques (Curasan system and PCCS) and a procedure used routinely in transfusion medicine. Platelet concentrates were prepared from venous blood of 12 healthy male volunteers using the three different systems. Platelet and leucocyte counts were performed and platelet derived growth factor and transforming growth factor beta were assayed by enzyme linked immunoassay. Handling was also considered. The three systems were able to collect 19.0 +/- 16.6% (laboratory system), 41.9 +/- 9.7% (Curasan system) and 49.6 +/- 21.0% (PCCS) of the absolute number of platelets which were originally in the venous blood volume within the platelet concentrate. Due to the amount of plasma which is left in the platelet concentrate portion, the platelet concentration could be increased between 1.4 +/- 1.3 times (laboratory system), 5.0 +/- 2.3 times (PCCS) and 11.7 +/- 2.4 times (Curasan system) compared to the venous blood. The amount of growth factors correlated with the number of platelets within the platelet concentrates. The two systems for intraoperative use are similar in their effects on the platelets. The absolute gain of platelets seems to be the highest with the PCCS; the highest concentration of platelets per micro L is gained with the Curasan system. The laboratory system may offer an alternative if an intraoperative system is not available.
Assuntos
Transfusão de Sangue Autóloga , Transfusão de Plaquetas , Plaquetoferese/métodos , Adulto , Plaquetas/fisiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Cuidados Intraoperatórios , Contagem de Leucócitos , Masculino , Plasma , Contagem de Plaquetas , Fator de Crescimento Derivado de Plaquetas/análise , Sistemas Automatizados de Assistência Junto ao Leito , Fatores de Tempo , Fator de Crescimento Transformador beta/análiseRESUMO
OBJECTIVE: To examine the effect of low-dose fish oil supplementation on specific growth factors, purported to play a central role in lesion formation, and also on the total growth factor activity of serum, as assessed by the induction of DNA synthesis in cultured human arterial smooth muscle cells. DESIGN: Randomized placebo-controlled double-blind intervention study. SETTING: Free-living population. SUBJECTS: Sixty-three healthy volunteers, 37 males and 26 females. INTERVENTIONS: Four treatment regimes with subjects receiving 0, 0.3,0.6 or 0.9 g/day of n-3 PUFA for an 8 week period. Blood samples were taken at baseline and following the 8 week intervention. All samples were analysed in batch following completion of the study. RESULTS: Consumption of fish oil had no effect on serum platelet-derived growth factor (PDGF), or transforming growth factor beta (TGFbeta) concentration. Furthermore, fish oil supplementation did not alter the total growth factor activity of serum. CONCLUSIONS: Results indicate that low-dose fish oil supplementation, equivalent to about two portions of fatty fish per week and providing less than 1 g n-3 PUFA/day, does not alter the levels of the major serum growth factors and does not modify total serum growth factor activity in healthy human volunteers. SPONSORSHIP: European Union shared cost project (FAIR-CT-95-0085).
Assuntos
Óleos de Peixe/administração & dosagem , Substâncias de Crescimento/sangue , Adulto , Arteriosclerose/prevenção & controle , DNA/biossíntese , Método Duplo-Cego , Ácidos Graxos Ômega-3/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Transformador beta/sangueRESUMO
PURPOSE: Remodeling of the extracellular matrix occurs in the lamina cribrosa in progressed glaucomatous optic nerve damage including disc cupping. We examined immunohistochemical changes in the transforming growth factor (TGF)-beta and platelet derived growth factor (PDGF) in the optic nerve heads in experimentally induced glaucoma. METHODS: We used 3 cynomolgus and 2 Japanese monkey eyes. Glaucoma was induced by repeated argon laser photocoagulation of the chamber angle. Eyes were enucleated after disc cupping had formed 3 to 5 months after treatment. The optic nerve head was examined for expression of TGF beta 1, beta 2, and beta 3, and PDGF A and B in frozen sections and by the biotin-ExtrAvidin-Alkali Phosphatase method. FINDINGS: Normal monkey eyes showed TGF beta 1, beta 2, and beta 3, and PDGF A, and B in the optic nerve head including the nerve fibers, glial cells, and vascular cells. Glaucomatous eyes showed stronger expression of TGF beta 1 and beta 2 in the glial cells around the lamina cribrosa. The staining intensities for TGF beta 3, PDGF A, and PDGF B were the same as in normal eyes. CONCLUSION: Eyes with experimental glaucoma showed higher expressions of TGF beta 1 and beta 2 around the lamina cribrosa. This finding may show upregulation of extracellular matrix production as related to remodeling of the lamina cribrosa in glaucoma.
Assuntos
Glaucoma/metabolismo , Disco Óptico/química , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Transformador beta/análise , Animais , Imuno-Histoquímica , Macaca , Macaca fascicularisRESUMO
OBJECTIVE: To characterize and identify the growth factors in human colostrum and to evaluate the importance of breast-feeding. METHODS: The activity of growth factors in human colostrum was determined by technique of 3H-TdR incorporation into cultured NIH-3T3 cells. The acid growth factor (CAGF) and basic growth factor (CBGF) were purified from human colostrum by a sequence of chromatography. The study of stability and SDS-PAGE was applied to identify the CAGF and CBGF. RESULTS: 0.5% (v/v) of human colostrum and 3.0% (v/v) of bovine serum had the same activity in stimulating DNA synthesis. The specific activity of human colostrum in stimulating DNA synthesis was 20 times greater than that of bovine serum. The activity of growth factors in human colostrum was higher than that in human milk or bovine colostrum, and only human colostrum contained two different kinds of growth factors--CAGF and CBGF. CONCLUSIONS: Human colostrum contains two kinds of growth factors. CAGF is epidermal growth factor like (EGF-like) growth factor and the CBGF is platelet differentiation growth factor like (PDGF-like) growth factor. The effects of human colostrum on promoting baby growth and development is stronger than that of human milk and bovine colostrum.
Assuntos
Colostro/química , Fator de Crescimento Epidérmico/análise , Fator de Crescimento Derivado de Plaquetas/análise , Células 3T3/metabolismo , Animais , DNA/biossíntese , Feminino , Humanos , Camundongos , GravidezRESUMO
The effect of low-dose fish oil supplementation on cytokines and white cell function in women was investigated. Thirty-three healthy, nonsmoking women entered the double-blind study. For 4 weeks, 2.4 g of either fish oil (n = 16) or fish oil with vitamin E (n = 17) was added daily to the subjects' otherwise unchanged diets. Venous blood samples were taken at the onset of the trial, after the supplementation period, and again after a 9-week washout period. Plasma levels of platelet-derived growth factor and myeloperoxidase were measured using immunoassays. The intracellular peroxidase content of white blood cells was measured using a staining technique. Platelet-derived growth factor levels were significantly lowered after supplementation (P < or = .05). Intracellular peroxidase was increased (P < or = .01), and extracellular myeloperoxidase levels were lowered (P < or = .05). Taken together, these results suggest that the anti-inflammatory effect of fish oil may be due at least partly to alterations in white cell function and growth factor levels.
Assuntos
Gorduras Insaturadas na Dieta/administração & dosagem , Óleos de Peixe/administração & dosagem , Leucócitos/efeitos dos fármacos , Peroxidase/sangue , Fator de Crescimento Derivado de Plaquetas/análise , Adolescente , Adulto , Citocinas/sangue , Método Duplo-Cego , Feminino , Humanos , Leucócitos/metabolismoRESUMO
BACKGROUND: Cytokines have profound effects on various aspects of granulomatous tissue formation. However, there is little information regarding their distribution during tissue development. This study investigated the temporal and spatial distribution of transforming growth factor-beta (TGF-beta), platelet-derived growth factor (PDGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1) and IL-1 beta in developing granulomatous tissue. EXPERIMENTAL DESIGN: Murine chronic granulomatous air pouches were induced and full thickness biopsies taken at intervals up to 28 days. Samples were prepared for immunohistochemistry and labeled using antibodies against TGF-beta, bFGF, PDGF, EGF, TNF-alpha, IL-1 alpha and IL-1 beta. RESULTS: Immunoreactivity to TGF-beta, PDGF, TNF-alpha, IL-1 alpha and IL-1 beta was localized to a proportion of macrophages within the granulomatous tissue. Immunopositive macrophage numbers increased with time, and with the exception of PDGF were associated with areas of fibrogenesis between days 14 to 28. Heterogeneous labeling of capillaries for EGF was observed within the granulomatous tissue juxtaposed to dermal musculature. Diffuse labeling of bFGF, associated with extracellular matrix, was always observed. After day 14, bFGF immunoreactivity was discretely localized to endothelial cells and the basement membrane of vessels within the granulomatous tissue. TGF-beta immunoreactivity was also associated with extracellular matrix components, being most intense in the area of fibrogenesis between 14 and 28 days. Occasional fibroblasts were also labeled with TGF-beta in this region. CONCLUSIONS: The spatial and temporal confinement of the individual cytokines suggests that a sequential coordinated process of repair and fibrosis is occurring. It is hoped that these observations will provide a more effective therapeutic approach for the sequential application of cytokines in abnormalities of wound healing.
Assuntos
Citocinas/biossíntese , Granuloma/metabolismo , Granuloma/patologia , Dermatopatias/metabolismo , Dermatopatias/patologia , Cicatrização , Animais , Óleo de Cróton , Citocinas/análise , Fator de Crescimento Epidérmico/análise , Fator de Crescimento Epidérmico/biossíntese , Feminino , Fator 2 de Crescimento de Fibroblastos/análise , Fator 2 de Crescimento de Fibroblastos/biossíntese , Imuno-Histoquímica , Inflamação , Interleucina-1/análise , Interleucina-1/biossíntese , Camundongos , Camundongos Endogâmicos , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Derivado de Plaquetas/biossíntese , Pele/metabolismo , Pele/patologia , Fatores de Tempo , Fator de Crescimento Transformador beta/análise , Fator de Crescimento Transformador beta/biossíntese , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Fibroblast growth factor (FGF)-1 and PDGF-B-like factors have been implicated in the pathobiology of RA and animal models of this disease. Since the receptors for FGF-1 and PDGF are tyrosine kinases, we examined the expression of tyrosine phosphorylated proteins (phosphotyrosine, P-Tyr) in synovial tissues from patients with RA and osteoarthritis (OA), and rats with streptococcal cell wall (SCW) and adjuvant arthritis (AA). Synovia from patients with RA and LEW/N rats with SCW and AA arthritis, in contrast to controls, stained intensely with anti-P-Tyr antibody. The staining colocalized with PDGF-B and FGF-1 staining. Comparative immunoblot analysis showed markedly enhanced expression of a 45-kD P-Tyr protein in the inflamed synovia. Treatment with physiological concentrations of dexamethasone suppressed both arthritis and P-Tyr expression in AA. P-Tyr was only transiently expressed in athymic nude Lewis rats and was not detected in relatively arthritis-resistant F344/N rats. These data suggest that (a) FGF-1 and PDGF-B-like factors are upregulated and may induce tyrosine phosphorylation of proteins in vivo in inflammatory joint diseases, (b) persistent high level P-Tyr expression is T lymphocyte dependent, correlates with disease severity, and is strain dependent in rats, (c) corticosteroids, in physiological concentrations, downregulate P-Tyr expression in these lesions.