Induction of ileum muscarinic cholinoceptor signal transduction pathways by rat interferon-gamma.
We have recently shown that rat interferon-gamma (IFN gamma) can trigger a cholinergic muscarinic response upon interaction with isolated rat atria, decreasing both the contractile tension and cAMP synthesis, and increasing cGMP production. Because the intestine is rich in cholinergic muscarinic receptors, and IFN gamma-producing cells are normal components of the mucosal immune system, we investigated whether IFN gamma could also modulate the muscarinic cholinergic activity of the intestine. Our results indicate that IFN gamma may interact with ileum cholinergic muscarinic receptors by inhibiting binding of the radiolabelled antagonist quinuclidinyl benzylate (3H-QNB), decreasing cAMP formation and increasing cGMP synthesis. These effects are associated with increased mechanical activity of the isolated ileum strips, and can be blunted by pretreatment of the tissue with atropine.
Sterin-Borda
L
L
CEFYBO-CONICET, Buenos Aires, Argentina.
Borda
E
E
Sales
M E
ME
Rodriguez
M
M
de Bracco
M M
MM
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D000242:Cyclic AMP / Q000032:analysis; D006152:Cyclic GMP / Q000032:analysis; D007082:Ileum / Q000187:drug effects* / Q000378:metabolism*; D007371:Interferon-gamma / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000187:drug effects; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000096:biosynthesis* / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*
D011976:Receptors, Muscarinic; D007371:Interferon-gamma; D000242:Cyclic AMP; D006152:Cyclic GMP