Search results for "Purinergic Antagonists"
showing 2 items of 2 documents
Co-transmitter mediated facilitation by sympathetic nerve stimulation of evoked acetylcholine release from the rabbit perfused atria preparation.
1995
Rabbit atria were isolated with the extrinsic right sympathetic and vagus nerves attached and perfused with Tyrode solution. Acetylcholine overflow was determined after labelling of the transmitter stores with [14C]choline and fractionation of the radioactivity on cation exchange columns. Sympathetic nerve stimulation (SNS, 2 Hz, 3 min) carried out together with vagus nerve stimulation (VNS, 2 Hz, 3 min), but each SNS pulse preceding a vagal one by 19 ms, caused a facilitation of acetylcholine overflow of about 60% versus independent controls in the absence of SNS. Antagonists of putative neurotransmitters were tested to find out the prejunctional mediator involved in the facilitation. The …
Evidence that ATP or a related purine is an excitatory neurotransmitter in the longitudinal muscle of mouse distal colon
2007
Background and purpose: This study analysed the contribution of the purinergic system to enteric neurotransmission in the longitudinal muscle of mouse distal colon. Experimental approach: Motor responses to exogenous ATP and to nerve stimulation in vitro were assessed as changes in isometric tension. Key results: ATP induced a concentration-dependent contraction, reduced by 4-[[4-formyl-5-hydroxy-6-methyl-3-[(phosphonooxy)methyl]-2-pyridinyl]azo]-1,3-benzene disulphonic acid (PPADS), suramin, P2Y purinoreceptor desensitisation with adenosine 5’-O-2-thiodiphosphate (ADPβS), and atropine, but unaffected by P2X purinoceptor desensitisation with α,β-methylene ATP (α,β-meATP) and by 2,2-dimethyl…