Experimental Thrombocytopenia or Leucocytopenia

Substances used to induce thrombocytopenia/ leucocytopenia (intravenous administration)  

Guinea pigs, hamsters, or mice are anesthetized with pentobarbital sodium (i.p.) and Rompun (i.m.) and placed on an electrically warmed table at 37 °C. The carotid artery is cannulated for blood withdrawal and the jugular vein is cannulated to administer the thrombocytopenia-inducing substances collagen + adrenaline (injection of the mixture of both within 10 s) or PAF or thrombin. In mice collagen + adrenaline are injected into a tail vein. 

Approx. 50-100 xl blood are collected into potassium-EDTA-coated tubes at times -1, 1 and 2 min (guinea pigs and mice) or 5, 10 and 15 min (rabbits) following the injection of the inducer. The number of platelets and leukocytes is determined within 1 h after withdrawal in 10 xl samples of whole blood using a microcellcounter suitable for blood of various animal species. 

The percentage of thrombocytes (or leukocytes) is determined in vehicle control and dosage groups at the different times following injection of the inducer relative to the initial value of control or dosage group, respectively. Calculated percent values of controls are taken as 100 %. 

Percent inhibition of thrombocytopenia (or leucocy-topenia) is calculated in dosage groups relative to controls. 

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