Platelets from patients with diabetes mellitus have impaired ability to mediate vasodilation.
OBJECTIVE
The purpose of this study was to examine vasomotor responses mediated by platelets from patients with diabetes mellitus.


BACKGROUND
Diabetes mellitus is associated with increased cardiovascular morbidity and mortality, which in part may be due to a variety of abnormalities reported in diabetic platelets. However, the effects of diabetic platelets on vasomotor tone have not been characterized.


METHODS
We compared platelet-mediated vasodilation elicited by platelets isolated from 30 healthy volunteers and 29 patients with diabetes mellitus as they were perfused through a preconstricted normal rabbit carotid artery.


RESULTS
Platelets from the diabetic patients mediated an impaired dilatory response in comparison with normal platelets: 2.7 +/- 2% versus 15.8 +/- 3.4% (p < 0.001) and 4.1 +/- 2.7% versus 32.7 +/- 3.3% (p < 0.001) (mean +/- SEM) increase in vessel diameter, for 5 X 10(7) and 1 X 10(8) platelets per milliliter perfused, respectively. The degree of impairment was similar for type I (insulin-dependent) and type II (non-insulin-dependent) diabetes mellitus. Normal platelets incubated in high D-glucose concentrations lost their ability to mediate dilation in a concentration-dependent and time-dependent manner. This was not true for incubation of normal platelets in high concentrations of L-glucose or insulin. However, there was not a significant correlation between glucose control in the diabetic patients and the ability of their platelets to mediate vasodilation.


CONCLUSIONS
Platelets from patients with diabetes mellitus have an impaired ability to mediate vasodilation. This impairment appears to be mediated by high glucose concentration. Further work is needed to elucidate the mechanisms for this abnormality in diabetic platelets.
Oskarsson
H J
HJ
Department of Internal Medicine, Section of Cardiology, University of Nebraska Medical Center, Omaha, USA.
Hofmeyer
T G
TG
D000328:Adult; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001792:Blood Platelets / Q000737:chemistry / Q000502:physiology*; D003920:Diabetes Mellitus / Q000503:physiopathology*; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D010974:Platelet Aggregation; D011817:Rabbits; D014664:Vasodilation; D014666:Vasomotor System / Q000503:physiopathology*
D001786:Blood Glucose; D007328:Insulin