Collagen-derived dipeptide Pro-Hyp administration accelerates muscle regenerative healing accompanied by less scarring after wounding on the abdominal wall in mice.

Collagens act as cellular scaffolds in extracellular matrixes, and their breakdown products may also have important biological functions. We hypothesize that collagen dipeptide Pro-Hyp induces favorable healing activities and examined the effects of Pro-Hyp administered via different routes on wound healing using our novel murine model, in which an advanced fibrosis-prone scar lesion was developed in the abdominal muscle wall under the skin. After excising a part of the abdominal wall, a free-drinking experiment was performed using solutions with casein (CS), high molecular weight collagen peptides (HP), and low molecular weight collagen peptides including Pro-Hyp and Hyp-Gly (LP), in addition to water (HO). On day 21 of the study, when compared to the HO and CS groups, muscle regeneration in the LP group was significantly advanced in the granulation tissue, which was associated with a decrease in fibrosis. To clarify the effects of Pro-Hyp, daily intraperitoneal administration of pure Pro-Hyp was performed. Pro-Hyp administration induced many myogenically differentiated cells, including myogenin-positive myoblasts and myoglobin-positive myocytes, to migrate in the granulation tissue, while scar tissue decreased. These results indicated that Pro-Hyp administration accelerates muscle regenerative healing accompanied by less scarring after wounding on the abdominal wall.

Development and characterization of oxaceprol-loaded poly-lactide-co-glycolide nanoparticles for the treatment of osteoarthritis.

Oxaceprol is well-defined therapeutic agent as an atypical inhibitor of inflammation in osteoarthritis. In the present study, we aimed to develop and characterize oxaceprol-loaded poly-lactide-co-glycolide (PLGA) nanoparticles for intra-articular administration in osteoarthritis. PLGA nanoparticles were prepared by double-emulsion solvent evaporation method. Meanwhile, a straightforward and generally applicable high performance liquid chromatography method was developed, and validated for the first time for the quantification of oxaceprol. To examine the drug carrying capacity of nanoparticles, varying amount of oxaceprol was entrapped into a constant amount of polymer matrix. Moreover, the efficacy of drug amount on nanoparticle characteristics such as particle size, zeta potential, morphology, drug entrapment, and in vitro drug release was investigated. Nanoparticle sizes were between 229 and 509 nm for different amount of oxaceprol with spherical smooth morphology. Encapsulation efficiency ranged between 39.73 and 63.83% by decreasing oxaceprol amount. The results of Fourier transform infrared and DSC showed absence of interaction between oxaceprol and PLGA. The in vitro drug release from these nanoparticles showed a sustained release of oxaceprol over 30 days. According to cell culture studies, oxaceprol-loaded nanoparticles had no cytotoxicity with high biocompatibility. This study was the first step of developing an intra-articular system in the treatment of osteoarthritis for the controlled release of oxaceprol. Our findings showed that these nanoparticles can be beneficial for an effective treatment of osteoarthritis avoiding side effects associated with oral administration.

Effects of dietary hydroxyproline on collagen metabolism, proline 4-hydroxylase activity, and expression of related gene in swim bladder of juvenile Nibea diacanthus.

This study was conducted to investigate the effects of dietary hydroxyproline (Hyp) on tissue collagen level, proline 4-hydroxylase (P4H) activity as well as transcript levels of COL1As (COL1A1 and COL1A2) and P4Hαs (P4Hα(I), P4Hα(II), and P4Hα(III)) in juvenile Nibea diacanthus. A total of 450 fishes were randomized to six equal groups and fed the diet with graded supplementary Hyp-0, 5, 10, 15, 20, and 25 g kg-1 of dry matter for 8 weeks. Results showed that fish fed diets with 10 g kg-1 Hyp had significantly higher acid-soluble collagen (ASC) and total collagen (TC) concentrations in swim bladder than fish fed with the other diets (P < 0.05). The activity of P4H in liver and swim bladder showed a similar trend, showing first increase and then decrease with increasing dietary Hyp (P < 0.05). The mRNA expression of COL1As in swim bladder and muscle were significantly higher than those in the liver and intestines. Meanwhile, with increasing dietary Hyp, the relative expression of COL1As genes in swim bladder showed a similar pattern with the TC concentrations of swim bladder, increased significantly initially followed by a decrease. Increased dietary Hyp content corresponded with significant decrease in the mRNA level of P4Hαs in swim bladder. These results indicated that the dietary Hyp promotes the collagen accumulation of swim bladder to some extent, and the promoting action may be related to the expression of COL1As. The optimum supplement of dietary Hyp was estimated from TC of swim bladder with piecewise regression analysis to be 9.66 g kg-1.

Metabolic profile and impact of diet in patients with primary hyperoxaluria.

PURPOSE: The primary goal of this pilot study was to evaluate metabolic characteristics and to examine the impact of diet in patients with primary hyperoxaluria (PH) under controlled, standardized conditions. METHODS: Four patients with genetically confirmed PH collected 24 h urines on their habitual, self-selected diets and on day 1, 6, 7, 8, and 11 under controlled, standardized conditions. The [13C2]oxalate absorption, calcium, and ammonium chloride loading tests were performed. RESULTS: While none of the patients had abnormal findings from the calcium loading test, incomplete distal renal tubular acidosis (RTA) was diagnosed in each of the four patients. Dietary intervention resulted in a significant decrease in urinary oxalate expressed as molar creatinine ratio (mmol/mol) between 30 and 40% in two of four patients. The evaluation of dietary records revealed a high daily intake of oxalate-rich foods as well as gelatin-containing sweets and meat products, rich sources of hydroxyproline, under the habitual, self-selected diets of the two responders. Intestinal oxalate hyperabsorption of 12.4% in one of the two patients may have additionally contributed to the increased urinary oxalate excretion under the individual diet. CONCLUSIONS: Our pilot data indicate that patients with PH may benefit from a restriction of dietary oxalate and hydroxyproline intake. Further research is needed to define the role of distal RTA in PH and to evaluate the hypothesis of an acquired acidification defect.

Comparative evaluation of therapeutic efficacy of intra-articular oxaceprol with conventional modalities in osteoarthritis animal model.

The duration and dose-dependent side effects of conventional intra-articular corticosteroid treatment in osteoarthritis (OA) like cartilage damage and chondrocyte toxicity warrant the search for alternative therapeutics. Oxaceprol, a recognized oral therapeutic agent for osteoarthritis, is yet to be explored for its intra-articular route of administration confirming better safety profile. In this study, a comparative evaluation of intra-articular oxaceprol and corticosteroid is carried out in osteoarthritis rabbit model. Osteoarthritis was induced by monosodium iodoacetate in rabbits. After randomization into three groups of five animals each: OA with intra-articular injection of saline, OA with intra-articular injection of oxaceprol, and OA with intra-articular injection of corticosteroids, treatment efficacy was analyzed by evaluation of inflammation through knee swelling, pain assessment by wire walking, and hot plate method. Further biopsies were collected for histological characterization. Intra-articular oxaceprol and corticosteroids reduced 20.5 and 24.5% knee swelling respectively within 4 weeks compared to those in control osteoarthritic rabbits. Oxaceprol exhibited analgesic action in visual analogue scoring of wire walking method. Hot plate test further confirmed drastic minimization of pain in oxaceprol intervention. Histological investigation suggested that application of oxaceprol has the abilities to protect articular cartilages from degenerative changes that occur in osteoarthritis. Marked improvement both in bone and cellular matrixes was observed in oxaceprol-treated group while gross lesions were visible and consisted of a well-demarcated area of cartilage erosion in control group. Intra-articular injection of oxaceprol showed remarkable improvement of articular cartilage in chemically induced osteoarthritic rabbits.

Integrative analysis of transcriptomics and metabolomics profiling on flesh quality of large yellow croaker Larimichthys crocea fed a diet with hydroxyproline supplementation.

A previous study showed that flesh quality of large yellow croaker (LYC) was improved by feeding dietary hydroxyproline (Hyp, 0·69 %). The aim of the present study was to explore the underlying mechanisms using transcriptomics and metabolomics analysis. The metabolomics analysis showed that muscle metabolite profiles could be clearly separated between the basal diet and Hyp supplementation diet. Metabolites including betaine, Hyp, lactate, glucose-6-phosphate, trimethylamine N-oxide, taurine, creatine, inosine monophosphate, histamine and serine made significant contribution to the separation. Compared with the control diet, the transcriptomics analysis identified a total of 334 different expressed genes, of which 298 genes were up-regulated and thirty-six genes were down-regulated in the Hyp supplementation group. The altered genes of the Hyp supplementation group were involved in collagen metabolism, lipid metabolism and energy metabolism. The integrated results revealed that the increased muscle collagen content in the Hyp supplementation diet was partly because of its enhancement of biosynthesis and the reduction of degradation. The improvement of muscle quality by dietary Hyp supplementation could also be related to a good utilisation of glucose through enhancement of glycolysis. It was concluded that dietary Hyp supplementation could improve flesh quality because of comprehensive metabolism changes including elevated collagen content, glycolysis, lipid metabolism and flesh flavour of LYC. The present study provided a novel strategy to understand the underlying molecular mechanism of flesh quality of LYC fed diet with Hyp supplementation.

Antibiotic Algae by Chemical Surface Engineering.

Chemical cell-surface engineering is a tool for modifying and altering cellular functions. Herein, we report the introduction of an antibiotic phenotype to the green alga Chlamydomonas reinhardtii by chemically modifying its cell surface. Flow cytometry and confocal microscopy studies demonstrated that a hybrid of the antibiotic vancomycin and a 4-hydroxyproline oligomer binds reversibly to the cell wall without affecting the viability or motility of the cells. The modified cells were used to inhibit bacterial growth of Gram-positive Bacillus subtilis cultures. Delivery of the antibiotic from the microalgae to the bacterial cells was verified by microscopy. Our studies provide compelling evidence that 1) chemical surface engineering constitutes a useful tool for the introduction of new, previously unknown functionality, and 2) living microalgae can serve as new platforms for drug delivery.

Calcium oxalate crystals and oxalate induce an epithelial-to-mesenchymal transition in the proximal tubular epithelial cells: Contribution to oxalate kidney injury.

TGF-ß1 is the main mediator of epithelial-to-mesenchymal transition (EMT). Hyperoxaluria induces crystalluria, interstitial fibrosis, and progressive renal failure. This study analyzed whether hyperoxaluria is associated with TGF-ß1 production and kidney fibrosis in mice and if oxalate or calcium oxalate (CaOx) could induce EMT in proximal tubule cells (HK2) and therefore contribute to the fibrotic process. Hyperoxaluria was induced by adding hydroxyproline and ethylene glycol to the mice's drinking water for up to 60 days. Renal function and oxalate and urinary crystals were evaluated. Kidney collagen production and TGF-ß1 expression were assessed. EMT was analyzed in vitro according to TGF-ß1 production, phenotypic characterization, invasion, cell migration, gene and protein expression of epithelial and mesenchymal markers. Hyperoxaluric mice showed a decrease in renal function and an increase in CaOx crystals and Ox urinary excretion. The deposition of collagen in the renal interstitium was observed. HK2 cells stimulated with Ox and CaOx exhibited a decreased expression of epithelial as well as increased expression mesenchymal markers; these cells presented mesenchymal phenotypic changes, migration, invasiveness capability and TGF-ß1 production, characterizing EMT. Treatment with BMP-7 or its overexpression in HK2 cells was effective at preventing it. This mechanism may contribute to the fibrosis observed in hyperoxaluria.

Effect of silver nanoparticles and hydroxyproline, administered in ovo, on the development of blood vessels and cartilage collagen structure in chicken embryos.

It has been considered that concentrations of certain amino acids in the egg are not sufficient to fully support embryonic development of modern broilers. In this study we evaluated embryo growth and development with particular emphasis on one of the major components of connective tissue, collagen. Experiments were performed on Ross 308 chicken embryos from 160 fertilised eggs. Experimental solutions of silver nanoparticles (Ag), hydroxyproline solution (Hyp) and a complex of silver nanoparticles with hydroxyproline (AgHyp) were injected into albumen, and embryos were incubated until day 20. An assessment of the mass of embryo and selected organs was carried out followed by measurements of the expression of the key signalling factors' fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor-A (VEGF-A). Finally, an evaluation of collagen microstructure using scanning electron microscopy was performed. Our results clearly indicate that Hyp, Ag and AgHyp administered in ovo to chicken embryos did not harm embryos. Comparing to the control group, Hyp, Ag and the AgHyp complex significantly upregulated expression of the FGF-2 at the mRNA and protein levels. Moreover, Hyp, Ag and, in particular, the complex of AgHyp significantly increased blood vessel size, cartilage collagen fibre lattice size and bundle thickness. The general conclusion from this study is that AgHyp treatment may help to build a stronger and longer lasting form of collagen fibres.

The effect of dietary hydroxyproline and dietary oxalate on urinary oxalate excretion in cats.

In humans and rodents, dietary hydroxyproline (hyp) and oxalate intake affect urinary oxalate (Uox) excretion. Whether Uox excretion occurs in cats was tested by feeding diets containing low oxalate (13 mg/100 g DM) with high (Hhyp-Lox), moderate (Mhyp-Lox), and low hyp (Lhyp-Lox) concentrations (3.8, 2.0, and 0.2 g/100 g DM, respectively) and low hyp with high oxalate (93 mg/100 g DM; Lhyp-Hox) to 8 adult female cats in a 48-d study using a Latin square design. Cats were randomly allocated to one of the four 12-d treatment periods and fed according to individual energy needs. Feces and urine were collected quantitatively using modified litter boxes during the final 5 d of each period. Feces were analyzed for oxalate and Ca, and urine was analyzed for specific density, pH, oxalate, Ca, P, Mg, Na, K, ammonia, citrate, urate, sulfate, and creatinine. Increasing hyp intake (0.2, 2.0, and 3.8 g/100 g DM) resulted in increased Uox excretion (Lhyp-Lox vs. Mhyp-Lox vs. Hhyp-Lox; P < 0.05), and the linear dose-response equation was Uox (mg/d) = 5.62 + 2.10 × g hyp intake/d (r(2) = 0.56; P < 0.001). Increasing oxalate intake from 13 to 93 mg/100 g DM did not affect Uox excretion but resulted in an increase in fecal oxalate output (P < 0.001) and positive oxalate balance (32.20 ± 2.06 mg/d). The results indicate that the intestinal absorption of the supplemental oxalate, and thereby its contribution to Uox, was low (5.90% ± 5.24%). Relevant increases in endogenous Uox excretion were achieved by increasing dietary hyp intake. The hyp-containing protein sources should be minimized in Ca oxalate urolith preventative diets until their effect on Uox excretion is tested. The oxalate content (up to 93 mg/100 g DM) in a diet with moderate Ca content does not contribute to Uox content.

Dietary hydroxyproline induced calcium oxalate lithiasis and associated renal injury in the porcine model.

BACKGROUND AND PURPOSE: We previously reported hyperoxaluria and calcium oxalate calculi in adult pigs (sows) fed hydroxyproline (HP). The purpose of this study was to grossly and histopathologically characterize intrarenal effects in this model. METHODS: In the swine facility at our campus, we maintained 21 gestating sows, of which 15 received daily treatment (5% HP mixed with dry feed) and 6 received no treatment (controls). Nine were sacrificed at 21 d (three control, six HP). All kidneys were extracted and examined grossly and for radiographic evidence of stones (GE CT scanner, 80kV, 400MA, 1 sec rotation, 0.625 mm slices). Papillary and cortical samples were processed for histologic analysis. RESULTS: Kidneys from treated sows showed significant calculi distributed within the renal papilla on CT, appeared mottled in the renal cortex and papillary areas, and had less distinct corticomedullary borders. Tiny crystals and mucinous debris lined the papillary tips, calices, and pelvis in kidneys from four of six treated sows, and multiple stones were noted at the papillary tips. Hematoxylin and eosin stain revealed crystals in collecting tubules and papillary tips in treated kidneys and none in controls. Yasue staining confirmed crystals in proximal periglomerular tubules of treated but not control animals. Tubular dilation and inflammatory/fibrotic changes were identified in kidneys from treated animals; none of these changes were evident in control kidneys. CONCLUSIONS: We report renal damage as a result of dietary-induced hyperoxaluria in adult sows. Specifically, we found crystalluria in proximal periglomerular tubules and collecting ducts, with tubular damage at all segments.

Improved methodology to induce hyperoxaluria without treatment using hydroxyproline.

The use of hydroxyproline (HP) to generate hyperoxaluria in the rat is a problem because it is impossible to separate the effect of oxalate on renal injury from the effects of HP and the large array of metabolic intermediates formed when HP is converted to oxalate. Previously, the Dahl salt-sensitive (SS) and Brown Norway (BN) rat strains were studied to determine genetic control of resistance or susceptibility to HP-induced renal injury and crystal deposition. To develop a better model to induce hyperoxaluria without causing injury from HP metabolites, animals were fed a diet containing various levels of added oxalate (0, 1, 2, 3, or 5%). After 5 weeks rats were killed and the kidneys were removed for microscopic evaluation of tubule changes and crystal deposition. The 3 and 5% oxalate-fed groups had a substantial increase in urine oxalate, about 50 and 140 µmol/g body weight over controls, respectively. Both the SS and BN 3% oxalate-fed animals showed only slightly elevated tubule area and no crystal deposition. However, BN animals fed 5% oxalate had a dramatic increase in their percent tubule areas compared to control BN rats and treated SS rats. Crystal deposition in the kidneys was only observed in the 5% oxalate-fed groups. The BN kidneys demonstrated a threefold higher crystal deposition compared to oxalate-fed SS rats. We conclude that oxalate-supplemented food is a better method of producing hyperoxaluria in the rat than using HP which may introduce metabolic intermediates injurious to the kidney.

Experimental induction of calcium oxalate nephrolithiasis in mice.

PURPOSE: The availability of various transgenic and knockout mice provides an excellent opportunity to better understand the pathophysiology of calcium oxalate stone disease. However, attempts to produce calcium oxalate nephrolithiasis in mice have not been successful. We hypothesized that calcium oxalate nephrolithiasis in mice requires increasing urine calcium and oxalate excretion, and experimentally induced hyperoxaluria alone is not sufficient. To provide evidence we induced hyperoxaluria by administering hyperoxaluria inducing agents in normocalciuric and hypercalciuric mice, and investigating various aspects of nephrolithiasis. MATERIALS AND METHODS: We administered ethylene glycol, glyoxylate or hydroxyl proline via diet in male and female normocalciuric B6 mice, and in hypercalciuric sodium phosphate co-transporter type 2 a -/- mice for 4 weeks. We collected 24-hour urine samples on days 0, 3, 7, 14, 21 and 28, and analyzed them for pH, creatinine, lactate dehydrogenase calcium and oxalate. Kidneys were examined using light microscopy. Urine was examined for crystals using light and scanning electron microscopy. RESULTS: Hypercalciuric mice on hydroxyl proline did not tolerate treatment and were sacrificed before 28 days. All mice on ethylene glycol, glyoxylate or hydroxyl proline became hyperoxaluric and showed calcium oxalate crystalluria. No female, normocalciuric or hypercalciuric mice showed renal calcium oxalate crystal deposits. Calcium oxalate nephrolithiasis developed in all mice on glyoxylate and in some on ethylene glycol. In all mice the kidneys showed epithelial injury. Male mice particularly on glyoxylate had more renal injury and inflammatory cell migration into the interstitium around the crystal deposits. CONCLUSIONS: Results confirm that hyperoxaluria induction alone is not sufficient to create calcium oxalate nephrolithiasis in mice. Hypercalciuria is also required. Kidneys in male mice are more prone to injury than those in female mice and are susceptible to calcium oxalate crystal deposition. Perhaps epithelial injury promotes crystal retention. Thus, calcium oxalate nephrolithiasis in mice is gender dependent, and requires hypercalciuria and hyperoxaluria.

Increased protein intake on controlled oxalate diets does not increase urinary oxalate excretion.

High animal protein intake is a risk factor for calcium oxalate stone disease. The effect of dietary protein on the urinary excretion of calcium, acid and citrate is well established. However, its effect on oxalate excretion is unclear, due in part to an inadequate control of dietary oxalate intake in previous studies. This relationship warrants clarification due to the proposed important role of the metabolism of amino acids in endogenous oxalate synthesis. In this study, 11 normal subjects consumed controlled oxalate diets containing 0.6, 1.2 and 1.8 g protein/kg body weight/day. The analysis of 24 h urine collections confirmed that as protein intake increased, urinary calcium and glycolate increased and urinary pH and citrate decreased. The increased glycolate excretion was due in part to an increased hydroxyproline, but not glycolate consumption. Total daily urinary oxalate excretion did not change. When indexed to creatinine there was a small but significant decrease in oxalate excretion. This is most likely due to hyperfiltration. These results indicate that as dietary protein intake increases, the catabolism of diet-derived amino acids is not associated with an increased endogenous oxalate synthesis in normal subjects.

Vitamin B6 deficiency augments endogenous oxalogenesis after intravenous L-hydroxyproline loading in rats.

The effects of an intravenous hydroxyproline load on endogenous oxalogenesis were compared in rats fed a standard diet or a vitamin B6-deficient diet. Twelve male Wistar rats were randomized to two groups and were fed either a standard diet (control group) or a vitamin B6-deficient diet for 3 weeks. Then the animals were intravenously administered 100 mg (762.6 micromol)/ml hydroxyproline. In the control group, infusion of hydroxyproline increased the 5-h urinary oxalate and glycolate excretion above baseline to 0.27% (2.02 +/- 1.11 micromol) and 0.32% (2.43 +/- 1.60 micromol) of the administered dose (mol/mol), while it was respectively 2.01% (15.24 +/- 2.13 micromol) and 0.00% (-0.02 +/- 0.19 micromol) of the dose in the vitamin B6-deficient group. Therefore, vitamin B6 deficiency augmented endogenous synthesis of oxalate from hydroxyproline by 7.56-fold (15.24/2.02) compared with that in the control group. Urinary citrate excretion was significantly lower at baseline and all other times in the vitamin B6-deficient group compared with the control group. In conclusions, L-hydroxyproline loading augmented endogenous oxalogenesis in the vitamin B6-deficient group without causing hyperglycolic aciduria, and also led to significant hypocitraturia. These findings suggest that hydroxyproline is not metabolized to oxalate via glycolate, but rather via the 4-hydroxyglutamate to glyoxylate pathway (usually requiring vitamin B6-dependent enzymes) even in the presence of vitamin B6 deficiency.

Concentração de hidroxiprolina como marcador bioquímico do dano músculo esquético após treinamento de resistência de força / Hydroxyproline of concentration as biomarker of muscle skeletal damage after endurance training

A geração de força elevada nas ações musculares excêntricas pode afetar as estruturas musculares e tendíneas do tecido conjuntivo. Por isso, o objetivo deste estudo foi comparar a concentração de hidroxiprolina antes e depois de um treino de resistência de força em 30RM, já que a hidroxiprolina pode ser utilizada como marcador do dano músculo esquelético. Foi necessário então, comparar o efeito agudo do treino de resistência de força na concentração de hidroxiprolina em oito homens com idades variando entre 17 e 25 anos. Uma coleta de urina basal e três testes de 30RM foram realizados, e após recuperação, executaram três séries de 30RM com outra coleta de urina feita duas horas depois. O tratamento estatístico dado para as médias da concentração de hidroxiprolina de pré e pós-treino, através do teste t-Student pareado, mostrou não haver diferença significativa (p>0,05). Assim, não foi possível inferir que houve algum dano por este método de análise.

The increased force due to the concentric and eccentric muscle actions may affect the connective tissue structures in muscle and tendon. So, this paper goal was to compare the hydroxyproline concentration before and after 30RM muscle endurance training, since hydroxyproline can be used as a biomarker of connective tissue damage. For such it was necessary to compare the muscle endurance training acute effect on the hydroxyproline concentration of 8 trained men whose ages varied between 17 and 25 years. A basal urine collection and a three 30RM test were performed. After the recovery, they performed three sets of 30RM and another urine collection two hours later was taken. The statistical treatment used to compare the averages oh the hydroxyproline concentration before and after training across paired Student t-test showed no significant difference (p>0.05). So, it is not possible to infer that there was no damage through this method of analysis.

Prodrug of proline analogue reduces hypoxic pulmonary hypertension in rats.

A polymeric prodrug of the proline analogue cis-4-hydroxy-l-proline (CHOP), poly(ethylene glycol)-lysine-CHOP or CHOP-PEG, prevents hypoxic pulmonary hypertension in rats by inhibiting collagen accumulation. A more potent prodrug was synthesized by increasing the loading of CHOP on the carrier from 14 to 100%. Pulmonary antihypertensive efficacy and pharmacokinetics are described in the rat hypoxia model. The antihypertensive effect of CHOP-PEG in rats exposed to 10% O2 for 7d showed approximately 2 x 10(2)-fold greater potency than monomeric CHOP. Routes of administration were compared to determine the lowest dose of CHOP-PEG that reduced right ventricular pressure approximately 50% vs. untreated hypoxic controls at 7d. Total doses required were: continuous s.c. via an osmotic minipump, 0.8 mg; single s.c., 10mg; single i.v., 40 mg; and single intratracheal 90 mg. Efficacy for at least 7d postdosing in pre-established pulmonary hypertension was shown. Using an ELISA-based assay, biphasic i.v. and stable s.c. pharmacokinetic profiles were observed 72 h after single injections and 7d after continuous s.c. infusion. Thus, this CHOP-PEG formulation prevents and reverses chronic hypoxic pulmonary hypertension in rats, is most effective when given by continuous s.c. infusion, and has favorable pharmacokinetic properties. Potent inhibitors of fibrosis appear to be promising agents in treating pulmonary hypertension and possibly other fibrosing diseases.

Efeito da anemia aguda na cicatrização de anastomoses colônicas: estudo experimental em ratos / Effect of the acute anemia in the healing of colonic anastomoses: experimental study in rats

Existem vários fatores, tanto locais como sistêmicos, que interferem na ocorrência das deiscências de anastomoses colônicas, como a vascularização da anastomose, técnica cirúrgica utilizada, uso de agentes farmacológicos e condições gerais do paciente,incluindo a anemia aguda. Esse estudo experimental teve como objetivo a avaliação da cicatrização da anastomose colônica em ratos na vigência de anemia aguda. Foram utilizados dois grupos de 20 ratos (grupo controle sem anemia e grupo com anemia aguda - provocada por punção da veia cava inferior com sangramento de 30por cento da volemia) submetidos a laparotomia para secção segmentar do cólon e confecção de anastomose término-terminal.Os animais foram sacrificados no 8º dia de pós-operatório. A anastomose, após uma análise macroscópica, foi estudada do ponto de vista bioquímico e histopatológico. Os resultados foram submetidos à análise estatística utilizando os testes de Fisher e de Mann Whitney, com nível de significância menor que 5por cento(p < 0,05).Os resultados histológicos foram consistentes com cicatrização alterada nos animais anêmicos. Os animais anêmicos apresentaram maior quantidade de fibrina e infiltrado monocitário, que são fatores deletérios na cicatrização e menor quantidade nos parâmetros dilatação linfática, congestão vascular e neoformação vascular, que são fatores adjuvantes na cicatrização de anastomoses. O presente estudo mostra que isoladamente a anemia aguda causa efeitos adversos negativos nos parâmetros histológicos da cicatrização de anastomoses colônicas.