The effect of platelet activating factor on pulmonary β‐adrenoceptors

1 An intravenous infusion of platelet activating factor (Paf) in the guinea‐pig elicits an increase in bronchial responsiveness to the spasmogens, histamine and bombesin. 2 Airways obstruction induced by bombesin in Paf‐treated animals is poorly reversed by isoprenaline compared to comparable airways obstruction induced by bombesin in vehicle‐treated animals. 3 Isoprenaline induced a comparable dose‐related relaxation in vitro of tracheal smooth muscle isolated from Paf‐ and vehicle‐treated animals. 4 No change in β‐adrenoceptor numbers or binding affinity was observed in lungs removed from Paf‐treated animals in comparison with those from vehicle‐treated animals, or after direct incubation with Paf in vitro. 5 The reduced bronchodilator responsiveness to isoprenaline in Paf‐treated animals is not related to changes in pulmonary β‐adrenoceptor function. These results suggest that non‐spasmogenic elements may contribute to airways obstruction induced in hyper‐responsive animals.

[1]  F. Cuss,et al.  EFFECTS OF INHALED PLATELET ACTIVATING FACTOR ON PULMONARY FUNCTION AND BRONCHIAL RESPONSIVENESS IN MAN , 1986, The Lancet.

[2]  K. Chung,et al.  Airway hyperresponsiveness induced by platelet-activating factor: role of thromboxane generation. , 1986, The Journal of pharmacology and experimental therapeutics.

[3]  K. Chung,et al.  Platelet Activating Factor Increases Vascular Permeability in Guinea Pig Airways , 1986 .

[4]  P. Braquet,et al.  Down-regulation of β2-adrenergic receptors by paf-acether and its inhibition by the paf-acether antagonist BN 52021 , 1985 .

[5]  B. Vargaftig,et al.  Ultrastructural evidence for extravascular platelet recruitment in the lung upon intravenous injection of platelet-activating factor (PAF-acether) to guinea-pigs. , 1985, British journal of experimental pathology.

[6]  G. Hunninghake,et al.  Late asthmatic responses: Inquiry into mechanisms and significance , 1985, Clinical reviews in allergy.

[7]  C. Page,et al.  THE PLATELET IN ASTHMA , 1984, The Lancet.

[8]  R. Patterson,et al.  The activity of aerosolized and intracutaneous synthetic platelet activating factor (AGEPC) in rhesus monkeys with IgE-mediated airway responses and normal monkeys. , 1983, The Journal of laboratory and clinical medicine.

[9]  S. Nahorski,et al.  β‐Adrenoceptor heterogeneity in guinea‐pig airways: comparison of functional and receptor labelling studies , 1983, British journal of pharmacology.

[10]  D. Cockcroft.  MECHANISM OF PERENNIAL ALLERGIC ASTHMA , 1983, The Lancet.

[11]  J. Fleiss,et al.  Some Statistical Methods Useful in Circulation Research , 1980, Circulation research.

[12]  C. Dollery,et al.  Demonstration of α1-adrenoceptors in guinea pig lung using 3H-prazosin , 1979 .

[13]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.