EFFECTS OF STREPTOZOTOCIN-INDUCED EXPERIMENTAL DIABETES AND INSULIN THERAPY ON PLATELET SEROTONIN UPTAKE AND VOLUME

Platelet serotonin uptake and mean platelet volume were measured in both healthy control and streptozotocin-induced diabetic rats with or without insulin treatment. The values of K-m and V-max were similar in all groups studied, and the individual values were unrelated to glycaemia and mean platelet volume. The platelet size in the diabetic+insulin group (4.82+/-0.12 fl; mean+/-SEM) and control group (4.78+/-0.08) was comparable, being higher in the diabetic group (5.22+/-0.13), and lower in the non-diabetic+insulin group (4.54+/-0.05) when compared with the control group. Plasma glucose levels were significantly correlated to mean platelet volume only in the diabetic+insulin group. We conclude that changes in platelet size in diabetes appear to be an effect of the lack of insulin. The data neither discards nor confirms that variations in the kinetics of platelet serotonin uptake contribute to the minor platelet amine contents in diabetic animals.