Transmitter in der Froschlunge

A comparison of the excitatory and inhibitory effects of non‐adrenergic, non‐cholinergic nerve stimulation and exogenously applied ATP on a variety of smooth muscle preparations from different vertebrate species

“…Some of these are excitatory, as for example those to the urinary bladder (Henderson & Roepke, 1934;Chesher, 1967;Dumsday, 1971;Burnstock, Dumsday & Smythe, 1972) and to segments of the gut in lower vertebrates (Everett, 1968;Carter, 1969;Bartlet & Hassan, 1971; Sneddon, Smythe, Satchell & Burnstock, to be published). Others are inhibitory, for example those to the amphibian and reptile lung (Wood & Burnstock, 1967;Campbell, 1971;Robinson, McLean & Burnstock, 1971;Berger, 1972;Schnizer, Hoang & Brecht, 1968) and parts of the vascular system (Hughes & Vane, 1967, 1970. It is not yet known whether any, some, or all of these nerves are purinergic or whether they release yet further neurotransmitters, although some evidence has been presented that those supplying the toad lung (Robinson et al, 1971), guinea-pig bladder (Dumsday, 1971;Burnstock et al, 1972), toad intestine (Sneddon et al, 1972) and rabbit portal vein (Hughes & Vane, 1967) may release ATP.…”

Distinctive pharmacological profile of a nonadrenergic inhibitory system in bullfrog lung

“…Previous studies in toad (Bufo marinus) lung have shown that the inhibitory innervation accompanies the vagus nerve (Wood & Burnstock, 1967;Campbell, 1971), and that the inhibitory effects of vagal stimulation can be prevented by ganglionic blockade (Wood & Burnstock, 1967;Campbell & Duxson, 1978), but not by atropine (Wood & Burnstock, 1967;Campbell, 1971). Similar inhibitory effects have been elicited in toad (B. maninus) and frog (Rana esculenta) lungs with ganglionic stimulants (Wood & Burnstock, 1967;Schnizer, Hoang & Brecht, 1968) such as dimethylphenylpiperazinium (DMPP). Although the response is easily elicited, very little is known about the inhibitory transmitter or transmitters involved.…”

“…Exogenously administered adrenaline (Carlson & Luckhardt, 1920;Brecht & Fraessle, 1944;Meves, 1953;Kobayasi & Yoda, 1960;Wood & Burnstock, 1967, Holmgren & Campbell, 1978, 5-hydroxytryptamine (Schnizer et al, 1968) and adenosine triphosphate (ATP) (Meves, 1953) produce some degree of relaxation of anuran lung, and there is evidence from previous studies supporting each of these agents as a putative transmitter for neurally mediated inhibition. Vasoactive intestinal peptide, which has been proposed as the transmitter for nonadrenergic, noncholinergic inhibition in mammalian airways (Matsuzaki, Hamaski & Said, 1980) has not been studied in anurans.…”

“…Vasoactive intestinal peptide, which has been proposed as the transmitter for nonadrenergic, noncholinergic inhibition in mammalian airways (Matsuzaki, Hamaski & Said, 1980) has not been studied in anurans. Adrenaline and 5-hydroxytryptamine have been identified in frog lung (R. esculenta) in relatively high concentrations (0.2 to 0.9 tig/g) and are released into perfusates during vagal stimulation (Schnizer et al, 1968). Both ,B-adrenoceptor antagonists (Wood & Burnstock, 1967; Schnizer et al, 1968) and drugs with anti-5-hydroxytryptamiine actions (Schnizer et al, 1968) have depressed neurally mediated relaxation of anuran lung.…”

“…Adrenaline and 5-hydroxytryptamine have been identified in frog lung (R. esculenta) in relatively high concentrations (0.2 to 0.9 tig/g) and are released into perfusates during vagal stimulation (Schnizer et al, 1968). Both ,B-adrenoceptor antagonists (Wood & Burnstock, 1967; Schnizer et al, 1968) and drugs with anti-5-hydroxytryptamiine actions (Schnizer et al, 1968) have depressed neurally mediated relaxation of anuran lung. However, since the concentrations of P-adrenoceptor antagonists used (approximately 10-4M), were considerably above those that produce selective effects on P-receptors, the observed antagonism could have resulted from depressant effects on ganglionic transmission or inhibitory transmitter release.…”