Effects of platelet depletion on PMA-induced acute lung injury in awake sheep.
Little is known about the role of circulating platelets in PMA-induced lung injury in vivo. We investigated the effects of platelet depletion (PD) on the injury using seven unanesthetized sheep with lung lymph fistulas and eight other sheep for morphological study. PD diminished a decrease in the lymph to plasma concentration ratio (L/P) after 1 microgram/kg PMA treatment (n = 4) and caused more increases in lung lymph flow, L/P and lung lymph clearance after 5 micrograms/kg PMA treatment (n = 3) than in control sheep. The high dose was lethal to platelet-depleted sheep. However, PD had no effects on pulmonary hemodynamics. Morphologically, alveolar hemorrhages and exudate, and bleb formation of type I epithelial cells were more prominent in the platelet-depleted sheep than in the control sheep. We conclude that circulating platelets have protective effects against PMA-induced lung injury but have little involvement in PMA-induced pulmonary hypertension.
Nakano
T
T
First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
Miyamoto
K
K
Aida
A
A
Saito
S
S
Nishimura
M
M
Kawakami
Y
Y
D000818:Animals; D001792:Blood Platelets / Q000276:immunology / Q000502:physiology*; D001798:Blood Proteins / Q000378:metabolism; D002199:Capillary Permeability; D006439:Hemodynamics / Q000187:drug effects; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D007106:Immune Sera; D007958:Leukocyte Count; D008168:Lung / Q000187:drug effects* / Q000648:ultrastructure; D008196:Lymph / Q000502:physiology; D008297:Male; D008854:Microscopy, Electron; D011650:Pulmonary Alveoli / Q000648:ultrastructure; D012756:Sheep; D013755:Tetradecanoylphorbol Acetate / Q000008:administration & dosage / Q000494:pharmacology*; D013929:Thromboxane B2 / Q000097:blood; D014617:Vacuoles / Q000648:ultrastructure
D001798:Blood Proteins; D007106:Immune Sera; D013929:Thromboxane B2; D013755:Tetradecanoylphorbol Acetate