ristocetin and Diabetes-Mellitus

Functional defects of platelets are often studied by in-vitro aggregation tests with chemical compounds such as ADP, epinephrine and ristomycin (ristocetin). The aim of the present work was to investigate the effect of some diseases and that of nonsteroidal anti-inflammatory drug treatment on platelet aggregation in dogs. The examination had been carried out on 115 dogs by a Carat TX4 optical aggregometer (Entec GmbH, Ilmenau, Germany) first used in veterinary practice. The dogs were divided in three groups: healthy (control) dogs (n = 43), diseased dogs with normal haemostasis profile (n = 44), and dogs suffering from arthropathies with normal haemostasis profile treated with the nonsteroidal anti-inflammatory drugs ketoprofen or carprofen (n = 21). Following establishment of normal platelet aggregation curves in healthy dogs we found that some diseases such as diabetes mellitus, Cushing's disease, mastocytoma and lymphoma increased or decreased the aggregation maximum of platelets or caused changes in the feature of the aggregation curve. Carprofen treatment had no effect on platelet aggregation while ketoprofen decreased the aggregation maximum. These results showed that Carat TX4 aggregometer proved a useful instrument in studying platelet aggregation in platelet-rich plasma of dogs. For clinical pathologists it is important to know that the effects of some diseases and nonsteroidal anti-inflammatory drug treatments have to be taken into account when in-vitro platelet aggregation is evaluated. Based on our results and on those of other studies, we think standardization in aggregation methodology is highly recommended in veterinary laboratories.

Topics: Adenosine Diphosphate; Animals; Anti-Inflammatory Agents, Non-Steroidal; Carbazoles; Case-Control Studies; Diabetes Mellitus; Dog Diseases; Dogs; Epinephrine; Ketoprofen; Neoplasms; Platelet Aggregation; Platelet Function Tests; Ristocetin

Topics: Adult; Aged; Blood Coagulation Factors; Diabetes Mellitus; Diabetic Retinopathy; Humans; Middle Aged; Platelet Aggregation; Ristocetin; von Willebrand Factor

Topics: Adult; Antigens; Arteriosclerosis; Cholesterol; Diabetes Complications; Diabetes Mellitus; Diabetic Retinopathy; Factor VIII; Fibrinogen; Fibrinolysis; Humans; Lipoproteins, HDL; Male; Middle Aged; Ristocetin

As impairment in coagulation and platelet function has been reported following acute administration of somatostatin, a reevaluation of the effects of the cyclic and linear form of the peptide was undertaken. In vitro somatostatin had no effect by itself on platelet aggregation and no effect on ADP- or ristocetin-induced aggregation. In vivo ten healthy men infused with cyclic or linear somatostatin (loading dose of 250 microgram and three hour-infusion with 1,500 microgram) and five control subjects were investigated during the infusion and for three hours after the end of the infusion. With this dose, sufficient in man for maintaining plasma growth hormone and insulin at fasting levels under arginine stimulation, no abnormalities in platelet count, in ADP-induced platelet aggregation and in plasma VIII von Willebrand factor, factor VIII procoagulant activity and factor VIII related antigen levels were observed.

Topics: Adenosine Diphosphate; Adult; Antigens; Blood Cell Count; Diabetes Mellitus; Factor VIII; Female; Humans; Male; Middle Aged; Platelet Aggregation; Ristocetin; Somatostatin; von Willebrand Factor

Topics: Adenosine Diphosphate; Blood Coagulation Factors; Diabetes Mellitus; Diabetic Retinopathy; Factor VIII; Humans; Hypophysectomy; Platelet Adhesiveness; Platelet Aggregation; Ristocetin