Blockade of nitric oxide synthesis modulates rat immunoglobulin A.
OBJECTIVE
Nitric oxide (NO) is known as a regulator of inflammation and immunity. The purpose of this study was to investigate the influence of this signal molecule on the rat immunoglobulin A (IgA) system using Nomega-nitro-L-arginine-methyl ester (L-NAME), which inhibits the activity of all isoforms of NO synthase.


METHODS
The experiments were performed on adult female Wistar rats showing diestrus day 1 that were treated with L-NAME (30 or 50 mg/kg, s.c.). Untreated and saline-injected animals were used as controls. The rats were sacrificed 3 h following L-NAME or saline administration. The concentration of IgA in serum and intestinal extracts was determined by a sandwich enzyme-linked immunosorbent assay. The number of IgA-expressing cells per area unit of Peyer's patches and the intestinal lamina propria was evaluated using stereological analysis.


RESULTS
The results showed that L-NAME decreased the level of IgA in serum and elevated its concentration in intestinal extracts. Additionally, the increased number of IgA+ cells was found in the intestinal lamina propria in both experimental groups.


CONCLUSIONS
Obtained findings imply that endogenous NO may modulate the IgA system in the rat.
Budec
Mirela
M
Department of Pathology and Cytology, Institute for Medical Research, University of Belgrade, Belgrade, Serbia. mirelab@imi.bg.ac.yu
Marković
Dragana
D
Djikić
Dragoslava
D
Mitrović
Olivera
O
Drndarević
Neda
N
Koko
Vesna
V
Todorović
Vera
V
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects / Q000502:physiology; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D041981:Gastrointestinal Tract / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D007108:Immune Tolerance / Q000187:drug effects / Q000502:physiology*; D007070:Immunoglobulin A / Q000097:blood*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D010581:Peyer's Patches / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; D007070:Immunoglobulin A; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester