0000000000740715
AUTHOR
Doris Erbelding
Tachykinin NK(2) receptors facilitate acetylcholine release from guinea-pig isolated trachea.
The release of newly synthesised [3H]acetylcholine was evoked by electrical field stimulation (5 Hz, 600 pulses) of epithelium-deprived guinea-pig trachea strips after sensory neuropeptides depletion with 3 microM capsaicin. The selective tachykinin NK(2) receptor agonist [betaAla(8)]neurokinin A-(4-10) increased in a concentration-dependent manner the electrically-induced release of [3H]acetylcholine. The facilitatory effect was antagonised by the selective non-peptide tachykinin NK(2) receptor antagonist, SR 48968 (apparent pK(B) 8.9). The tachykinin NK(1) and NK(3) receptor agonists substance P methyl ester and senktide (both 10 and 100 nM), respectively, did not affect the evoked releas…
Differential effects of anandamide on acetylcholine release in the guinea-pig ileum mediated via vanilloid and non-CB1 cannabinoid receptors
The effects of anandamide on [3H]-acetylcholine release and muscle contraction were studied on the myenteric plexus-longitudinal muscle preparation of the guinea-pig ileum preincubated with [3H]-choline. Anandamide increased both basal [3H]-acetylcholine release (pEC50 6.3) and muscle tone (pEC50 6.3). The concentration-response curves for anandamide were shifted to the right by 1 μM capsazepine (pKB 7.5 and 7.6), and by the combined blockade of NK1 and NK3 tachykinin receptors with the antagonists CP99994 plus SR142801 (each 0.1 μM). The CB1 and CB2 receptor antagonists, SR141716A (1 μM) and SR144528 (30 nM), did not modify the facilitatory effects of anandamide. Anandamide inhibited the e…
Modulation by NO of acetylcholine release in the ileum of wild-type and NOS gene knockout mice.
Nitric oxide (NO) inhibits the release of acetylcholine and cholinergic contractions in the small intestine of several species, but no information is available about the mouse ileum. This study examines the effects of NO on the electrically evoked release of [3H]acetylcholine and smooth muscle contraction in myenteric plexus-longitudinal muscle preparations of wild-type mice and of neuronal NO synthase (nNOS) and endothelial NOS (eNOS) knockout mice. The NOS inhibitor N G-nitro-l-arginine (l-NNA) and the guanylyl cyclase inhibitor 1 H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ) concentration dependently increased the evoked [3H]acetylcholine release and cholinergic contractions in prepa…