Prostaglandin unstable angina

Modesti PA, Colella A, Cedoni I, Costoli A, Biagini D, Migliorini A, Semeri GGN. Increased number of thromboxane Aj-prostaglandin Hj platelet receptors in active unstable angina and causative role of enhanced thrombin formation. Am Heart J 1995 129 873-9... 

Aspirin Irreversibly inhibits cyclooxygenase. Thus prevents formation of thromboxane A2 and prostaglandins (which induce platelet aggregation). Reduce risk of recurrent transient ischemic attacks or stroke. Reduces risk of myocardial infarction in patients with unstable angina or prior infarction. Also used for antiinflammatory and analgesic purposes. Gl ulceration, bleeding, hemorrhage, salicylism. 

As well as the apparent pathological role that thromboxane A2 plays in unstable angina, it also seems to be involved in the transient ischaemic attacks that occur in stroke patients. Aspirin is recommended by the FDA for treating these patients. The evaluation of thromboxane synthase inhibitors and prostaglandin endoperoxide-thromboxane A2 receptor antagonists in the clinical setting will doubtless reveal pathological roles for thromboxane A2 in other human diseases. 

Figure 6.8 Urinary, 2,3-dinor-thromboxane (Tx) B2 (normal < 350 pg/mg creatinine) and 2,3-dinor-6-keto-prostaglandin (PG) (normal < 220 pg/mg creatinine) in 6h urine aliquots over 2 days in a patient admitted with unstable angina who subsequently developed an acute myocardial infarction...

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