Autori: N. Alexandru , I. Jardín, D. Popov , M. Simionescu , J. García-Estan, G. M. Salido, J. A. Rosado

Editorial: L.M. Popescu, Wiley-Blackwell, J. Cell. Mol. Med. , 12, No 5B, p.2015-2026, 2008.

Rezumat:

Type 2 diabetes mellitus induces a characteristic platelet hyperactivity that might be due to several factors including oxidative stress and abnormal intracellular Ca2+ homeostasis. Hyperhomocysteinaemia is considered a risk factor in the development of
thrombosis although its effect on platelet function and the mechanisms involved are still poorly understood. Here we show that homocysteine induces a concentration-dependent increase in endogenous production of reactive oxygen species (ROS), which was
significantly greater in platelets from diabetic patients than in controls. Platelet treatment with homocysteine resulted in Ca2+ release from the dense tubular system and the acidic stores. Ca2+ mobilization-induced by homocysteine consisted in two components,an initial slow increase in intracellular free Ca2+ concentration ([Ca2+]i) and a rapid and marked increase in [Ca2+]i, the second leading to the activation of platelet aggregation. As well as ROS generation, Ca2+ mobilization and platelet aggregation were significantly greater in platelets from diabetic donors than in controls, which indicate that platelets from diabetic donors are
more sensitive to homocysteine. These findings, together with the hyperhomocysteinaemia reported in diabetic patients, strongly suggest that homocysteine might be considered a risk factor in the development of cardiovascular complications associated to type 2 Diabetes mellitus.

Cuvinte cheie: trombina, homocisteina, agregare, plachete, cai de semnalizare ale calciului // thrombin, homocysteine, aggregation, platelets, calcium signalling • ROS production

URL: http://www3.interscience.wiley.com/journal