A comparison between ATP and bradykinin as possible mediators of the responses of smooth muscle to non-adrenergic non-cholinergic nerves

Evidence that NO acts as a redundant NANC inhibitory neurotransmitter in the guinea‐pig isolated taenia coli

“…Also, we did not address the identity of NDHF either here or in our previous study in the rat anococcygeus. However, in the guinea‐pig taenia coli, the similar time course of relaxations to ATP and those to NANC nerve stimulation as well as the abolition of ATP‐mediated relaxation with apamin, is consistent with previous suggestions that ATP is a NANC transmitter, at least in this tissue (Burnstock, 1972; Ferraro et al , 1980; Costa et al , 1986; Den Hertog et al , 1989; Hoyle et al , 1990; Burnstock, 1990). Since PACAP‐mediated relaxations in the guinea‐pig taenia coli are also similar to those to NANC nerve stimulation and are blocked by apamin (Schworer et al , 1992), it too needs to be considered as a candidate for NDHF.…”

The nature of non‐cholinergic, non‐adrenergic transmission in longitudinal and circular muscles of the guinea‐pig ileum

“…Bradykinin (BK) has a similar action to the stimulation of non-ch., non-adr. nerves in different tissues; namely, the guinea-pig taenia coli, the rat duodenum (Ferrero et al 1980), the rat colon (Hawa et al 1981) and the guinea-pig distal colon (Eaglesom & Zeitlin, 1978). BK and SP had much the same influence on the membrane properties and also on the non-ch., non-adr.…”

“…transmitters (VIP, SP and BK; Matsuzaki et al 1980;Franco, Costa & Furness, 1979a;Ferrero et at. 1980) localized in the enteric neurons (Jessen, Saffrey, Van Noorden, Bloom, Polak & Burnstock, 1980;Probert, De Mey & Polak, 1981) were also investigated in relation to the non-ch., non-adr.…”

“…We also assessed the effects of other putative transmitters (substance P, vasoactive intestinal polypeptide and, bradykinin) since these agents mimic the non-ch., non-adr. nerve mediated responses in some intestinal and tracheal preparations (Franco, Costa & Furness, 1979b;Matsuzaki, Hamasaki & Said, 1980;Ferrero, Cocks & Burnstock, 1980).…”

Non-adrenergic inhibition of the longitudinal muscle of rabbit distal colon may not be mediated by purinergic nerves

“…caused mainly an intestinal stimulation through activation of cholinergic non-nicotinic receptors. Finally, Ferrero et al (1980) argued that another endogenous substance (bradykinin) appeared to be a serious contender for the transmitter role in the nonadrenergic nerves at least in both guinea-pig taenia caeci and the rat duodenum. The present study was undertaken to examine the possible role of purinergic mechanisms in the electrically-induced non-adrenergic relaxation of the longitudinal coat of the distal colon of the rabbit.…”