Effect of intravenous platelet-activating factor on bovine pulmonary mast cells.
The effect of platelet-activating factor (PAF) on bovine pulmonary mast cells (MCs) was investigated in calves aged 1-4 months. PAF was administered over a 5-min period at a rate of 50 ng/kg/min to six animals, which were killed approximately 10 min later. No macroscopical lesions were observed in the lung tissue of five control calves. On semi-thin toluidine-blue stained sections, MC cytoplasm showed profuse deep-blue granulation. In the lung tissues of PAF-treated calves, striking interstitial, alveolar and interlobular oedema and emphysema were observed. MC granules occurred at the periphery of the cytoplasm and MC nuclei were easily detectable. Moreover, the number of granules in the MC cytoplasm was remarkably low. A few granules with some metachromatic material were sometimes detected outside the cell limits. Ultrastructurally, the matrix pattern of the MC granules in lung tissues of control calves was either amorphous or granular. In lung tissues of the PAF-treated calves, the granular matrix pattern was pronounced, varying from fine- to coarse-grained, and the MCs were of reduced size, with many filiform processes and exocytotic vesicles. These findings indicate that pulmonary MC degranulation was induced by PAF in healthy calves.
Jolly
S
S
Department of Anatomy, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B-43, B-4000 Liège, Belgium.
Thomas
C
C
Genicot
B
B
Dessy-Doizé
C E
CE
Coignoul
F L
FL
Desmecht
D
D
D000818:Animals; D002417:Cattle; D015550:Cell Degranulation / Q000187:drug effects; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000648:ultrastructure; D007275:Injections, Intravenous / Q000662:veterinary; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D010972:Platelet Activating Factor / Q000008:administration & dosage / Q000494:pharmacology*
D010972:Platelet Activating Factor