Biomaterial Database

Vascular effects of platelet-activating factor in lambs: role of cyclo- and lipoxygenase. 1992

H Toga, and S Hibler, and B O Ibe, and J U Raj

Department of Pediatrics, Harbor-University of California, Los Angeles Medical Center, Torrance 90509.

In adult sheep, platelet-activating factor (PAF) effects include systemic hypotension and pulmonary hypertension. To identify developmental differences in vascular responses to PAF, we studied the effects of C18- and C16-PAF in 49 +/- 2- (SE) day-old lambs. Responses of upstream (arteries and microvessels) and venous segments of the lung to C18-PAF were determined both in vivo and in isolated lungs. In isolated lungs, the role of eicosanoids in PAF effects was also determined. In vivo, both C18- and C16-PAF caused a significant increase in systemic and pulmonary vascular resistance. The magnitude of vascular responses to C16-PAF was greater than that to C18-PAF. C18-PAF constricted both upstream and venous segments of the pulmonary circulation. Cyclooxygenase inhibition in isolated lungs attenuated arterial constriction to C18-PAF, whereas simultaneous cyclooxygenase and lipoxygenase inhibition completely blocked the effects of C18-PAF. In summary, in contrast to PAF effects in adult sheep, PAF constricts both systemic and pulmonary vessels in lambs, with significant pulmonary venous constriction. Eicosanoids, especially lipoxygenase products, play a major role in mediating PAF effects in the lung.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008833	Microcirculation	The circulation of the BLOOD through the MICROVASCULAR NETWORK.	Microvascular Blood Flow,Microvascular Circulation,Blood Flow, Microvascular,Circulation, Microvascular,Flow, Microvascular Blood,Microvascular Blood Flows,Microvascular Circulations
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D010972	Platelet Activating Factor	A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.	AGEPC,Acetyl Glyceryl Ether Phosphorylcholine,PAF-Acether,Phosphorylcholine, Acetyl Glyceryl Ether,1-Alkyl-2-acetyl-sn-glycerophosphocholine,Platelet Aggregating Factor,Platelet Aggregation Enhancing Factor,Platelet-Activating Substance,Thrombocyte Aggregating Activity,1 Alkyl 2 acetyl sn glycerophosphocholine,Aggregating Factor, Platelet,Factor, Platelet Activating,PAF Acether,Platelet Activating Substance
D011451	Prostaglandin-Endoperoxide Synthases	Enzyme complexes that catalyze the formation of PROSTAGLANDINS from the appropriate unsaturated FATTY ACIDS, molecular OXYGEN, and a reduced acceptor.	Fatty Acid Cyclo-Oxygenase,PGH Synthase,Prostaglandin H Synthase,Prostaglandin Synthase,Prostaglandin-Endoperoxide Synthase,Arachidonic Acid Cyclooxygenase,Cyclo-Oxygenase,Cyclooxygenase,Cyclooxygenases,Hydroperoxide Cyclase,PGH2 Synthetase,Prostaglandin Cyclo-Oxygenase,Prostaglandin Cyclooxygenase,Prostaglandin Endoperoxide Synthetase,Prostaglandin G-H Synthase,Prostaglandin H2 Synthetase,Prostaglandin Synthetase,Cyclase, Hydroperoxide,Cyclo Oxygenase,Cyclo-Oxygenase, Fatty Acid,Cyclo-Oxygenase, Prostaglandin,Cyclooxygenase, Arachidonic Acid,Cyclooxygenase, Prostaglandin,Endoperoxide Synthetase, Prostaglandin,Fatty Acid Cyclo Oxygenase,G-H Synthase, Prostaglandin,Prostaglandin Cyclo Oxygenase,Prostaglandin Endoperoxide Synthases,Prostaglandin G H Synthase,Synthase, PGH,Synthase, Prostaglandin,Synthase, Prostaglandin G-H,Synthase, Prostaglandin H,Synthase, Prostaglandin-Endoperoxide,Synthases, Prostaglandin-Endoperoxide,Synthetase, PGH2,Synthetase, Prostaglandin,Synthetase, Prostaglandin Endoperoxide,Synthetase, Prostaglandin H2
D011652	Pulmonary Circulation	The circulation of the BLOOD through the LUNGS.	Pulmonary Blood Flow,Respiratory Circulation,Circulation, Pulmonary,Circulation, Respiratory,Blood Flow, Pulmonary,Flow, Pulmonary Blood,Pulmonary Blood Flows
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D002302	Cardiac Output	The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).	Cardiac Outputs,Output, Cardiac,Outputs, Cardiac
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations