Release of plasminogen activator by pentosan polysulphate

Transient Postoperative Hemorrhage from Elbow Arthroscopy Portals following Intra-Articular Pentosan Polysulfate Sodium Injection

Four adult, client owned dogs with diagnosed bilateral elbow dysplasia undergoing elbow arthroscopy for removal of fragmented medial coronoid process were identified via a retrospective database search, who also received intra-articular administration of pentosan polysulfate sodium (PPS) (Cartrophen Vet, Biopharm Australia Pty Ltd., Bondi Junction, New South Wales). Dogs had postoperative administration of 5 ml PPS injected into each elbow joint following elbow arthroscopy. Within 1-3 hours of administration, each dog experienced hemorrhage from arthroscopy incisions that was determined to be independent of surgical trauma given lack of hemorrhage intraoperatively. Pressure bandages were placed, and the hemorrhage and elevated coagulation parameters resolved 12-18 hours following intra-articular injection. No further intervention was required, and the dogs were discharged 20-26 hours postoperatively. The purpose of this case series is to describe 4 dogs who experienced transient and focal hemorrhage following off-label intra-articular administration of pentosan polysulfate sodium (PPS). While this case series is limited due to small number of cases, results following bilateral, intra-articular injection of PPS support a transient systemic coagulopathy. Though this report represents administration of PSS via a route and at doses beyond that recommended on the label, results suggest that administration of PSS in the manner described in this report should be avoided.

Post-transcriptional, post-translational and pharmacological regulation of tissue factor pathway inhibitor

: Tissue factor (TF) pathway inhibitor (TFPI) is an endogenous natural anticoagulant that readily inhibits the extrinsic coagulation initiation complex (TF-FVIIa-Xa) and prothrombinase (FXa, FVa and calcium ions). Alternatively, spliced TFPI isoforms (α, β and δ) are expressed by vascular and extravascular cells and regulate thrombosis and haemostasis, as well as cell signalling functions of TF complexes via protease-activated receptors (PARs). Proteolysis of TFPI plays an important role in regulating physiological roles of the TF pathway in host defense and possibly haemostasis. Elimination of TFPI inhibition has therefore been proposed as an approach to improve haemostasis in haemophilia patients. In this review, we focus on posttranscription and translational modification of TFPI and its function in thrombosis and how pharmacological inhibitors and endogenous proteases interfere with TFPI and alter haemostasis.

Calcium pentosan polysulfate and sodium pentosan polysulfate may be used to treat intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a major health problem world-wide, and several spinal disorders are closely associated with it. Although people have invested a great deal of time and effort, how to prevent and reverse the IDD for the researchers is still a difficult and hot issue. Intervertebral disc belongs to cartilage tissue, and IDD also is the cartilage degeneration disease. A large quantity of studies have shown that Calcium pentosan polysulfate (CaPPS) and sodium pentosan polysulfate (NaPPS) possess chondroprotective activities and play an important role in maintaining cartilage integrity. We reasonably hypothesize that NaPPS and CaPPS may be used to treat IDD. The possible mechanism may include that: (1) the significant effects of NaPPS and CaPPS in improving capillary blood flow could maintain nutritional supply to intervertebral disc, and preserve intervertebral disc tissue against degeneration; (2) CaPPS and NaPPS preserve cartilage integrity, proteoglycan synthesis, and improve cartilage biomechanical properties; (3) as the multifaceted exosite inhibitors of proteinases NaPPS and CaPPS strongly impede the activity and production of proteinases; (4) promotion of the balance between proteinases and TIMPs also may be involved in treating IDD; (5) NaPPS and CaPPS exhibit potent anti-inflammatory effects, and then reduce inflammation-induced IDD. If the hypothesis were conformed, the symptoms caused by IDD and its related diseases would be a corresponding alleviation or even disappearance, which could greatly alleviate the suffering of patients from disc degeneration diseases. Certainly, many roles of CaPPS and NaPPS, such as effectiveness, safety and side effects, need to be tested, and further works such as animal model and clinical trial, need to be done to prove this hypothesis.

Comparative study on the in vitro and in vivo activities of heparinoids derivative investigated on the animal model

In this study we compared the antithrombotic and anticoagulant properties of sodium and calcium derivatives of pentosan polysulfate (Na-PPS, Ca-PPS), unfractionated heparin (UFH), and low-molecular-weight heparin (Fraxiparin). The antithrombotic effects of these agents have been investigated in an experimental thrombosis model in which rat mesenteric venules with a diameter of 20-30 microm were injured by well-defined argon laser lesions. Furthermore, the in vivo and in vitro anticoagulant activities [activated partial thromboplastin time (aPTT), Heptest] of these agents have been studied. Thrombus formation was significantly inhibited after s.c. injection of Na-PPS and Ca-PPS in doses >10 mg/kg. The duration of the antithrombotic effect lasted 8 h for Na-PPS and 12 h for Ca-PPS. After oral administration of Na-PPS, an antithrombotic effect was not observed. Oral application of Ca-PPS in doses >20 mg/kg significantly inhibited thrombus formation. Na-PPS and Ca-PPS markedly prolonged clotting time in aPTT and Heptest in concentrations ranging from 0.01 to 0.2 mg/ml rat PTT. Two h after s.c. administration of these agents in a dose of 10 mg/kg, the aPTT increased threefold and the Heptest 2.5-fold compared with controls. After oral application of 50 mg/kg Na-PPS and Ca-PPS, no effect on the coagulation test could be measured. Intravenous injection of UFH prolonged the Heptest after 1 min and the aPTT after 30 min. In ex vivo studies of aPTT and Heptest performed in rat plasma between 2 and 24 h after s.c. injection of 0.2 mg/kg Fraxiparin, no inhibition of any coagulation test was measured. The antithrombotic effect of 0.2 mg/kg Fraxiparin after s.c. injection was significant. Intravenous injection of 20 U/kg UFH significantly inhibited thrombus formation. The smallest antithrombotic effect was after i.v. injection of UFH.

The pathobiology of osteoarthritis and the rationale for the use of pentosan polysulfate for its treatment

OBJECTIVES

Structure-modifying osteoarthritis (OA) drugs (SMOADs) may be defined as agents that reverse, retard, or stabilize the underlying pathology of OA, thereby providing symptomatic relief in the long-term. The objective of this review was to evaluate the literature on sodium pentosan polysulfate (NaPPS) and calcium pentosan polysulfate (CaPPS), with respect to the pathobiology of OA to ascertain whether these agents should be classified as SMOADs.

METHODS

Published studies on NaPPS and CaPPS were selected on the basis of their relevance to the known pathobiology of OA, which also was reviewed.

RESULTS

Both NaPPS and CaPPS exhibit a wide range of pharmacological activities. Of significance was the ability of these agents to support chondrocyte anabolic activities and attenuate catabolic events responsible for loss of components of the cartilage extracellular matrix in OA joints. Although some of the anti-catabolic activities may be mediated through direct enzyme inhibition, NaPPS and CaPPS also have been shown to enter chondrocytes and bind to promoter proteins and alter gene expression of matrix metalloproteinases and possibly other mediators. In rat models of arthritis, NaPPS and CaPPS reduced joint swelling and inflammatory mediator levels in pouch fluids. Moreover, synoviocyte biosynthesis of high-molecular-weight hyaluronan, which is diminished in OA, was normalized when these cells were incubated with NaPPS and CaPPS or after intraarticular injection of NaPPS into arthritic joints. In rabbit, canine, and ovine models of OA, NaPPS and CaPPS preserved cartilage integrity, proteoglycan synthesis, and reduced matrix metalloproteinase activity. NaPPS and CaPPS stimulated the release of tissue plasminogen activator (t-PA), superoxide dismutase, and lipases from vascular endothelium while concomitantly decreasing plasma levels of the endogenous plasminogen activator inhibitor PAI-1. The net thrombolytic and lipolytic effects exhibited by NaPPS and CaPPS may serve to improve blood flow through subchondral capillaries of OA joints and improve bone cell nutrition. In geriatric OA dogs, NaPPS and CaPPS reduced symptoms, as well as normalized their thrombolytic status, threshold for platelet activation, and plasma triglyceride levels. These hematologic parameters were shown to be abnormal in OA animals before drug treatment. Similar outcomes were observed in OA patients when CaPPS or NaPPS were given orally or parenterally in both open and double-blind trials.

CONCLUSIONS

The data presented in this review support the contention that NaPPS and CaPPS should be classified as SMOADs. However, additional long-term clinical studies employing methods of assessing joint structural changes will be needed to confirm this view.

Slow-acting, disease-modifying osteoarthritis agents

There is evidence to suggest that tetracyclines have benefit beyond their antimicrobial activity. The ability to inhibit metalloproteinase activity may provide a disease-modifying effect in OA, and available data suggest that further investigation is warranted. Controlled, double-blind, prospective clinical studies have not been completed. The canine cruciate ligament transection model studies are frequently cited as the most convincing in vivo evidence of a benefit of oral tetracycline therapy for the treatment of OA. Until more evidence becomes available, the use of tetracyclines as therapeutic agents for OA should be considered investigational.

Pharmacology and special clinical applications of low-molecular-weight heparins

In this overview, the rationale of the development of low-molecular-weight (LMW) heparins and their toxicological, anticoagulant, fibrinolytic, lipolytic, and protamine interactions are summarized. Clinical experiences are reviewed on the benefit of LMW heparin for anticoagulation in patients with bleeding and other complications on conventional anticoagulants and during pregnancy. It is concluded that animal experiments have demonstrated the safety of LMW heparins, that the pharmacologic profile is improved compared with normal heparin, and that the simple and safe applicability of LMW heparins gives rise to new indications for the long-term prophylaxis of thromboembolism.