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 bo th healthy control and streptozotocin-induced diabetic rats with or wi thout insulin treatment. The values of K-m and V-max were similar in a ll groups studied, and the individual values were unrelated to glycaem ia 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) wa s comparable, being higher in the diabetic group (5.22+/-0.13), and lo wer in the non-diabetic+insulin group (4.54+/-0.05) when compared with the control group. Plasma glucose levels were significantly correlate d to mean platelet volume only in the diabetic+insulin group. We concl ude that changes in platelet size in diabetes appear to be an effect o f the lack of insulin. The data neither discards nor confirms that var iations in the kinetics of platelet serotonin uptake contribute to the minor platelet amine contents in diabetic animals.