Dose response of enoxaparin at the cremaster muscle flap microcirculation

Abstract

The effects of different dosages of enoxaparin (Lovenox), a low molecular-weight heparin, on microcirculation were investigated. The cremaster muscle model for intravital microscopy was used. Four groups were studied: in group I (n = 6), the controls no agent was given; in group II (n = 6), enoxaparin (2 mg/kg s.c.), in group III, (n = 6), enoxaparin (4 mg/kg s.c.); and in group IV, (n = 6), exoxaparin (8 mg/kg s.c.). These agents were injected before muscle dissection. All animals were observed under intravital microscopy, and measurements of capillary density and red blood cell velocity were taken at 2, 3, 5, and 7 h following subcutaneous enoxaparin injection. Statistical analysis revealed that the capillary density significantly increased in group II and group III, respectively, (by 33% (P < 0.0001) and 25% (P < 0.01) when compared to group I at the fifth hour. Group IV was not significantly different from group I in capillary density. There was no significant difference in red blood cell velocity in any of the groups. Propensity for bleeding was not observed in any of the groups during the dissections and observation periods except in group IV. In conclusion subcutaneous administration of 2 mg/kg enoxaparin improves (by 33%) capillary density without any bleeding complications at the cremaster muscle flap microcirculation at the fifth hour following injection (P < 0.0001). (c) 2005 Wiley-Liss, Inc. Microsurgery 25:147-151, 2005.

Preventive effects of enoxaparin and hesperidin in cerulein-induced acute pancreatitis in rats

“…The ROS in the pancreatic tissues were significantly higher in CRL-induced rats than in the control animals in our study, and our results conform to those previously reported in literature (4,8,24). This study demonstrates the powerful therapeutic potential of the concomitant use of 2 agents-HES (17)(18)(19) and ENX (12,13,15)-that are clinically applied for their anticoagulant or anti-inflammatory properties. To our knowledge, ours is the first study where HES was used to treat acute pancreatitis.…”

“…ENX is a lowmolecular-weight heparin that is widely used in surgery. ENX is a potent vasodilator, and it inhibits platelet aggregation and thrombosis, increases capillary permeability and perfusion effectively, and scavenges ROS considerably (12)(13)(14)(15)(16). There is no consensus in literature concerning the effects of anticoagulants in inflammation and pancreatitis.…”

Anticoagulation Therapy in Microsurgery: A Review

“…34 Lower doses (2 mg/kg) of subcutaneous LMWH (enoxaparin) were most effective at dilating capillaries (by 33%) without bleeding complications in an animal model. 53 Ertas et al 53 reported significant capillary dilation in rat cremaster muscle 5 hours after administration of 2 mg/kg and 4 mg/kg LMWH. The efficacy of higher LMWH doses (8 mg/kg) was no different than control, but caused markedly increased bleeding.…”

Effects of Clopidogrel and Low-Molecular-Weight Heparin on Viability of Random Skin Flaps in Rats

“…17,20 The doses and treatment duration were chosen based on previous studies on this subject, to obtain a better comparison. 21,22 The pathophysiology of necrosis due to ischemia is complex, involving vascular insufficiency as a consequence of arterial vasospasm mediated by vasoactive substances, production of free radicals, swelling of endothelial cells, inactivation of sodium and potassium pumps, and thrombotic venous congestion. 4,23 Two important mechanisms have been implicated in postsurgical damage: neutrophilic influx and vascular thrombosis.…”

“…Enoxaparin has potent anticoagulant activity, with a lower propensity for bleeding than unfractionated heparin. 21 Low-dose enoxaparin also exerts anti-inflammatory effects in animal models and in humans, so its therapeutic effects may be attributable to a combination of anticoagulant and anti-inflammatory properties. 10 However, some researchers maintain that its anticoagulant activity is key, based on microcirculatory changes.…”