title: Platelet sequestration during hypothermia in dogs treated with sulphinpyrazone and ticlopidine--reversibility accelerated after intra-abdominal rewarming.
abstract: During body cooling, a progressive thrombocytopenia is observed, with platelet sequestration mainly in the liver. Platelets return progressively to the circulation during rewarming. In this work the presence of platelet clumps is demonstrated by electron microscopy inside the hepatic sinusoids of dogs cooled to 20 degrees C by immersion in iced water. Such clumps were not found either before cooling or after body rewarming. Similar platelet clumps in the hepatic microcirculation were found in two other groups of dogs cooled and rewarmed as before, but previously treated with the antiaggregants sulphinpyrazone or ticlopidine. Another group of dogs was cooled and rewarmed by intra-abdominal circulation of physiological saline respectively at 4 degrees C and 40 degrees C. In these animals a similar decrease of circulating platelets was observed. However, just after rewarming was started, with the body temperature still at 22 degrees C, sequestered platelets came back abruptly to circulation. We conclude that hepatic platelet sequestration induced by hypothermia appears mainly due to local haemodynamic conditions.
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000473:pathology*; D004285:Dogs; D006439:Hemodynamics; D006358:Hot Temperature; D007035:Hypothermia / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D008099:Liver / Q000473:pathology; D010974:Platelet Aggregation / Q000187:drug effects; D013442:Sulfinpyrazone / Q000494:pharmacology*; D013876:Thiophenes / Q000494:pharmacology*; D013921:Thrombocytopenia / Q000209:etiology; D013988:Ticlopidine
chemical_list: D013876:Thiophenes; D013988:Ticlopidine; D013442:Sulfinpyrazone