[Modulatory effects of polyamines and GABA on rat ileal motility in vitro].
OBJECTIVE
The aim of our work was to determine the effects of polyamines and GABA on rat ileum motility in vitro.


METHODS
Longitudinal strips dissected from control ileum or ileum without myenteric plexus after benzalkonium chloride (BAC) treatment were placed in organ bath chambers.


RESULTS
Spermine significantly inhibited spontaneous activity and nerve stimulation-induced response. Inhibition of spontaneous activity was not altered by BAC treatment or tetrodotoxin but was antagonized by BAY K 8644, a L-type calcium channel agonist. Spermine inhibitory effect on nerve-stimulation induced response disappeared after BAC treatment. GABA enhanced the response induced by nerve stimulation but did not antagonize spermine effects; its action was inhibited in presence of atropine and was mimicked by baclofen, a GABAB agonist.


CONCLUSIONS
Polyamines and GABA can modulate rat ileum motility in vitro. GABA acted via neural GABAB receptors. We demonstrate for the first time that spermine exerts a dual action through different mechanisms on both smooth muscle cells and probably intramural neurons.
Bayer
S
S
INSERM U338, Groupe de Physiopathologie Digestive, Strasbourg.
Raul
F
F
Boehm
N
N
Klein
A
A
Angel
F
F
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D001548:Benzalkonium Compounds / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004558:Electric Stimulation; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007082:Ileum / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D011073:Polyamines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013096:Spermine / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D001548:Benzalkonium Compounds; D002121:Calcium Channel Blockers; D011073:Polyamines; D013096:Spermine; D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester