Biomaterial Database

Pathophysiological mechanisms of sudden death induced by platelet activating factor. 1984

A M Lefer, and H F Müller, and J B Smith

Platelet activating factor (Paf) (15-40 micrograms-1) kills male rabbits within 3 to 5 min. Intravenous injection of Paf at a dose of 15 micrograms kg-1 is uniformly lethal, and the rabbits died within 4.5 +/- 0.4 min. The sudden death is characterized by cessation of respiration, a marked decrease in mean arterial blood pressure (M.A.B.P.), and 8 fold increases in plasma thromboxane B2 (TxB2) concentrations with only modest elevation in plasma 6 keto-prostaglandin F1 alpha (6-keto PGF1 alpha) concentrations. Pretreatment with the cyclo-oxygenase inhibitor, ibuprofen (6.25 mg kg-1), or with the thromboxane synthetase inhibitors dazoxiben (2.5 mg kg-1), CGS-13080, or OKY-046 1 mg kg-1) increased survival rates to 83-100%. Protected rabbits showed only modest changes in M.A.B.P. and no significant increase in plasma TxB2 concentrations. The protective drugs showed a dose-related action on M.A.B.P., plasma TxB2 concentration and mortality rate in Paf-induced sudden death. The mechanisms of the protection appeared to be prevention of platelet aggregation (leading to pulmonary thrombosis) and pulmonary and coronary vasoconstriction. However, Paf does not appear to exert direct vasoconstrictor effects in isolated coronary or pulmonary arteries. The effects of Paf in vivo appear to be mediated by TxA2 released by activated platelets in the absence of the protective effects of prostacyclin. Inhibition of thromboxane synthesis effectively prevents the Paf-induced sudden death.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
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
D011651	Pulmonary Artery	The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.	Arteries, Pulmonary,Artery, Pulmonary,Pulmonary Arteries
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
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
D003645	Death, Sudden	The abrupt cessation of all vital bodily functions, manifested by the permanent loss of total cerebral, respiratory, and cardiovascular functions.	Sudden Death
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