Microvascular injury induced by intravascular platelet aggregation. An experimental study.
Microvascular injury due to platelet aggregation was studied in cats for an hour after 1-hour intraaortic infusion of a suspension of collagen fibrils. Haematocrit and numbers of circulating platelets and leukocytes were repeatedly measured in arterial blood and a major cutaneous lymph vessel in the thigh was cannulated for measurement of lymph flow and erythrocyte counts in peripheral lymph. There were seven groups, each of eight cats, viz. normal cats infused with collagen (I) or vehicle (II) and collagen-infused cats which were platelet-depleted--by antiserum (III), or neutrophil-depleted--by anti-serum (IV), or decomplemented--by cobra venom (V), or pretreated with indomethacin--10 mg/kg (VI), or treated with nonimmunized serum (VII). Induced intravascular platelet aggregation reduced the numbers of circulating platelets and leukocytes, and increased haematocrit, lymph flow and numbers of red cells in peripheral lymph. These effects were inhibited by platelet depletion and indomethacin and attenuated by decomplementation and neutrophil depletion. Platelet aggregation was thus shown to induce microvascular injury and increase microvascular permeability, which is partly dependent on complement and neutrophils.
Vaage
J
J
Institute of Physiology, University of Oslo, Norway.
D000818:Animals; D002199:Capillary Permeability; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D002415:Cats; D003094:Collagen; D003165:Complement System Proteins / Q000502:physiology; D004906:Erythrocyte Count; D006400:Hematocrit; D006614:Hindlimb; D008196:Lymph / Q000502:physiology; D008833:Microcirculation / Q000293:injuries*; D009504:Neutrophils / Q000502:physiology; D015539:Platelet Activation; D010974:Platelet Aggregation; D010976:Platelet Count
D003094:Collagen; D003165:Complement System Proteins