Substance P activates leukocytes and platelets in rabbit microvessels.
The effect of substance P on leukocytes and platelets in rabbit skeletal muscle microvasculature was studied by intravital microscopy and electron microscopy. Local application of substance P caused vasodilatation and formation of aggregates of platelets and leukocytes in postcapillary venules with subsequent migration of leukocytes through the vessel wall. Many neutrophils were partially degranulated. Aggregate formation induced by substance P could not be prevented by autacoid antagonists. However, superfusion with calcitonin gene-related peptide prior to challenge with substance P greatly inhibited aggregate formation and leukocyte extravasation.
Ohlén
A
A
Department of Physiology I, Karolinska Institutet, Stockholm, Sweden.
Thureson-Klein
A
A
Lindbom
L
L
Persson
M G
MG
Hedqvist
P
P
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D002465:Cell Movement / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000648:ultrastructure; D004731:Endotoxins / Q000032:analysis; D007962:Leukocytes / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D008833:Microcirculation / Q000648:ultrastructure; D009132:Muscles / Q000098:blood supply; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D010974:Platelet Aggregation / Q000187:drug effects; D011817:Rabbits; D013373:Substance P / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D004731:Endotoxins; D013373:Substance P