Cutaneous and pulmonary histopathological responses to platelet activating factor (Paf-acether) in the guinea-pig.
The effect of synthetic Paf-acether has been studied in guinea-pig skin, following intradermal injection, and in guinea-pig lung, following intravenous administration. Histopathological responses to Paf-acether were assessed by both light microscopy and electron microscopy. In addition, plasma protein extravasation and platelet accumulation were quantitatively assessed using radiolabelling techniques. Intradermal injection of Paf-acether, but not lyso-Paf, elicited acute increased vascular permeability, accompanied by intravascular accumulation of platelets and neutrophils. There was evidence, 2-8 h after intradermal injection of Paf-acether, of perivascular infiltration with neutrophils. At 24 h there was a mixed cellular infiltrate comprising mononuclear cells in addition to neutrophils. Following systemic administration of Paf-acether, aggregates of platelets in close association with neutrophils were evident within the pulmonary vasculature. Intravenous injection of Paf-acether, but not lyso-Paf, caused intrathoracic accumulation of radiolabelled platelets. These results suggest that Paf-acether has properties consistent with those of a mediator of inflammation.
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D002199:Capillary Permeability / Q000187:drug effects; D006168:Guinea Pigs; D007271:Injections, Intradermal; D007275:Injections, Intravenous; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D008297:Male; D008854:Microscopy, Electron; D009504:Neutrophils / Q000187:drug effects; D010972:Platelet Activating Factor / Q000008:administration & dosage / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D012867:Skin / Q000187:drug effects* / Q000473:pathology
D001798:Blood Proteins; D010972:Platelet Activating Factor