Enoxaparin--a low molecular weight heparin,restores the altered vascular reactivity of resistance arteries in aged and aged-diabetic hamsters

We questioned whether the low molecular weight heparin enoxaparin acts upon the altered vascular reactivity of the resistance arteries in normal biological aging and in aging associated with diabetes. Experiments were performed on isolated resistance arteries of young (4 months old), aged (16 months old), and aged-diabetic hamsters (16 months old and 5 months since streptozotocin injection), and the reactivity was assessed by the myograph technique. The results showed that enoxaparin (60 microg/ml) had favorable effects on the vascular reactivity in aged and aged-diabetic conditions, i.e., diminished the contractility of the arterial wall to 10(-8)-10(-6) M noradrenaline (NA) and to K(+), and potentiated the impeded endothelium-dependent relaxation to 10(-8)-10(-4) M acetylcholine (ACh). The effect was more pronounced compared to that produced by unfractionated heparin (UFH). These pharmacological effects supplement the anticoagulant properties of enoxaparin and may be of relevance for improving perfusion/circulation in the microvasculature of aged and of aged-diabetic persons.