Biomaterial Database

Role of thromboxane A2 in the cardiovascular response to intracoronary C5a. 1990

G L Stahl, and E A Amsterdam, and J D Symons, and J C Longhurst

Department of Internal Medicine, University of California, Davis 95616.

Intracoronary administration of complement component C5a induces transient decreases in coronary blood flow and regional left ventricular segment shortening, associated with intramyocardial granulocyte trapping. We evaluated the influence of a cyclooxygenase inhibitor (acetylsalicylic acid, n = 8) or a thromboxane A2/prostaglandin H2 receptor antagonist (SQ29548, n = 6) on these C5a-induced cardiovascular responses. Open-chest anesthetized pigs were instrumented to monitor heart rate, arterial blood pressure, left anterior descending coronary blood flow, regional left ventricular segment shortening, and dP/dt. Oxygen content, lactate concentration, leukocyte count, and thromboxane B2, the stable metabolite of thromboxane A2, were measured in arterial and regional coronary venous blood. Repetitive injections of intracoronary C5a (500 ng) given 60 minutes apart showed no tachyphylaxis of the hemodynamic response. However, tachyphylaxis was seen in coronary blood flow changes when injections were spaced 30 minutes apart. An increase in myocardial oxygen extraction and lactate production was observed after intracoronary C5a. Administration of acetylsalicylic acid (50 mg/kg i.v.) attenuated C5a-induced decreases in coronary blood flow (-8 +/- vs. -3 +/- 1 ml/min) and regional left ventricular segmental shortening (-10 +/- 3% vs. -2 +/- 1%) and blocked the maximal increase in coronary venous thromboxane B2 (2.0 +/- 0.1 vs. 0.2 +/- 0.1 pmol/ml plasma). Furthermore, SQ29548 (30 micrograms/kg/min) reduced C5a-induced changes in coronary blood flow (-13 +/- 2 vs. -4 +/- 2 ml/min) and segmental shortening (-14 +/- 2% vs. -3 +/- 1%). Neither cyclooxygenase inhibition nor thromboxane A2/prostaglandin H2 antagonism blocked the decrease in coronary venous granulocyte count.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007267	Injections	Introduction of substances into the body using a needle and syringe.	Injectables,Injectable,Injection
D008297	Male		Males
D002319	Cardiovascular System	The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.	Circulatory System,Cardiovascular Systems,Circulatory Systems
D003331	Coronary Vessels	The veins and arteries of the HEART.	Coronary Arteries,Sinus Node Artery,Coronary Veins,Arteries, Coronary,Arteries, Sinus Node,Artery, Coronary,Artery, Sinus Node,Coronary Artery,Coronary Vein,Coronary Vessel,Sinus Node Arteries,Vein, Coronary,Veins, Coronary,Vessel, Coronary,Vessels, Coronary
D005231	Fatty Acids, Unsaturated	FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.	Fatty Acids, Polyunsaturated,Polyunsaturated Fatty Acid,Unsaturated Fatty Acid,Polyunsaturated Fatty Acids,Acid, Polyunsaturated Fatty,Acid, Unsaturated Fatty,Acids, Polyunsaturated Fatty,Acids, Unsaturated Fatty,Fatty Acid, Polyunsaturated,Fatty Acid, Unsaturated,Unsaturated Fatty Acids
D005260	Female		Females
D006834	Hydrazines	Substituted derivatives of hydrazine (formula H2N-NH2).	Hydrazide
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013618	Tachyphylaxis	Rapidly decreasing response to a drug or physiologically active agent after administration of a few doses. In immunology, it is the rapid immunization against the effect of toxic doses of an extract or serum by previous injection of small doses. (Dorland, 28th ed)