Platelet sensitivity in vitro to adenosine-5′-diphosphate and prostacyclin and diabetic retinopathy

Abstract

Platelet sensitivity to adenosine diphosphate and prostacyclin in diabetes has been assessed using collision theory and the concept of 'sticking probability' (the probability of particle union). Twenty Type 1 (insulin-dependent) diabetic men (10 with no or minimal retinopathy and a matched group of 10 with proliferative retinopathy) and 10 age-matched non-diabetic men were studied. Platelets from the 20 diabetic patients required, on average, 37% less adenosine diphosphate to achieve a sticking probability of 0.5 (ED50) compared with platelets from the non-diabetic subjects (medians 1.50 and 0.95 μmol/l, respectively; p<0.01). The platelet prostacyclin response was assessed by the dissociation constant (Ki) for inhibition of adenosine diphosphate-induced aggregation. Platelets from the diabetic patients had similar prostacyclin sensitivity to those from the non-diabetic subjects (medians 0.42 and 0.42 respectively). Diabetic patients with and without retinopathy had similar platelet sensitivity to both adenosine diphosphate and prostacyclin. © 1985 Springer-Verlag.