Inhibitory action of glucosamine on platelet activation in guinea pigs.
OBJECTIVE
Glucosamine, a naturally occurring amino monosaccharide, has been used to treat or prevent osteoarthritis in humans. Recently, we have revealed that glucosamine inhibits platelet activation in vitro. However, the effect of in vivo administration of glucosamine has not yet been clarified. In this study, we administered glucosamine orally to guinea pigs and examined its effects on platelet functions.


METHODS
Glucosamine hydrochloride solution (0.5%, 5 mg/ml) was administered orally to guinea pigs ad libitum for 22 days, and platelet rich plasma was collected to evaluate platelet functions in vitro. Guinea pigs received an average of 400 mg glucosamine/animal/day.


RESULTS
Glucosamine-administration suppressed platelet aggregation in response to ADP by 51% (p < 0.01), but not platelet aggregation induced by collagen. Furthermore, glucosamine-administration inhibited the ADP-induced extracellular release of ATP and production of thromboxane A(2) by 91% and 96%, respectively (p < 0.001). In contrast, glucosamine did not affect the body-weights, platelet counts and bleeding time in guinea pigs after the administration.


CONCLUSIONS
These observations suggest that glucosamine is likely to exert an inhibitory action on platelets in vivo by suppressing platelet aggregation, ATP release, and thromboxane A(2) production. Thus, glucosamine could be expected as a novel and safe anti-platelet agent.
Lu-Suguro
J F
JF
Department of Host Defense and Biochemical Research, Juntendo University, School of Medicine, 2-1-1 Hongo, Tokyo 113-8421, Japan.
Hua
J
J
Sakamoto
K
K
Nagaoka
I
I
D000244:Adenosine Diphosphate / Q000378:metabolism / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D001760:Bleeding Time; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003594:Cytoplasmic Granules / Q000378:metabolism; D005260:Female; D005944:Glucosamine / Q000008:administration & dosage / Q000494:pharmacology*; D006168:Guinea Pigs; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D013928:Thromboxane A2 / Q000378:metabolism
D018048:Receptors, Purinergic P2; D013928:Thromboxane A2; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D005944:Glucosamine