Absence of mast cell involvement in leukocyte adhesion and emigration induced by inhibition of nitric oxide synthase.
Leukocyte adhesion on venules and their emigration to extravascular connective tissue are induced by administration of a nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester. In the present study, the involvement of mast cells in the process was examined in genetically mast cell-deficient and normal rats by intravital microscopy. Superfusion of the NOS inhibitor into the mesentery induced partial degranulation of mast cells in normal rats. However, leukocyte adhesion on mesenteric venules and emigration to extravascular connective tissue occurred even in mast cell-deficient rats, with no significant difference from the normal rats. When the reverse-passive Arthus reaction, characterized by generalized antigen-antibody complex formation, was induced in the rat mesentery, the immune complex increased both the adhesion and emigration in normal rats but not in mast cell-deficient rats. These results show that mast cells are not involved in the leukocyte adhesion and emigration induced by NOS inhibition, but are in the reverse-passive Arthus reaction.
Kosaka
H
H
Second Department of Physiology, Kagawa Medical University, Kita, Japan.
Seiyama
A
A
Terada
N
N
Yoneyama
H
H
Hirota
S
S
Kitamura
Y
Y
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002452:Cell Count / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007962:Leukocytes / Q000166:cytology* / Q000502:physiology; D008297:Male; D008407:Mast Cells / Q000166:cytology* / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D014699:Venules / Q000166:cytology / Q000502:physiology
D004791:Enzyme Inhibitors; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester