title: The involvement of prostaglandins and thromboxanes in the response to pulmonary embolism in anaesthetized rabbits and isolated perfused lungs.
abstract: Embolisation of blood clots produced an increased pulmonary artery pressure in vitro and systemic hypotension in vivo. In control anaesthetized animals, systemic blood pressure fell by 44.9 +/- 28.0 mm Hg following embolisation and 40% of the animals died within 5 minutes of embolisation. Plasma concentrations of thromboxane B2 (TXB222222 2) and 6-keto-prostaglandin F 1 alpha (6-keto-PGF 1 alpha) were increased by 0.54 +/- 0.13 ng/ml and 0.41 +/- 0.25 ng/ml, respectively. Pretreatment of animals with aspirin (ASA), 5 mg/kg or 250 mg/kg, reduced the hypotensive response and the TXB 2 and 6-keto-PGF 1 alpha release. Embolisation of isolated lungs perfused with blood-free medium induced an increase in pulmonary artery pressure of 32.7 +/- 21.0 mm Hg and significantly increased the content of TXB 2 and 6-keto-PGF 1 alpha in the perfusate. Pretreatment of lungs with indomethacin, 10 micrograms/ml, reduced the mean pulmonary pressure response to embolisation to 10.6 +/- 4.9 mm Hg and blocked the appearance of TXB 2 in the perfusate. Embolisation with an agarose clot induced only a 2.58 +/- 0.8 mm Hg increase in pressure and no detectable TXB 2 release. These results indicate that embolisation of lungs with a blood clot induces the release of TXB 2 and 6-keto-PGF 1 alpha. The release of these mediators, the hemodynamic responses and mortality were blocked by ASA pretreatment.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis*; D000768:Anesthesia, General; D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D007022:Hypotension / Q000209:etiology; D007213:Indomethacin / Q000494:pharmacology; D008168:Lung / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D011312:Pressure; D011651:Pulmonary Artery; D011655:Pulmonary Embolism / Q000150:complications / Q000378:metabolism*; D011817:Rabbits; D013929:Thromboxane B2 / Q000096:biosynthesis*; D013931:Thromboxanes / Q000096:biosynthesis*
chemical_list: D013931:Thromboxanes; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D001241:Aspirin; D007213:Indomethacin