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The roles of acetylcholine, dopamine, octopamine, tyramine, 5-hydroxytryptamine, histamine, glutamate, 4-aminobutanoic acid (gamma-aminobutyric acid) and a range of peptides as insect neurotransmitters are evaluated in terms of the criteria used to identify transmitters. Of the biogenic amines considered, there is good evidence that acetylcholine, dopamine,(More)
The nine Leucophaea Tachykinin-Related Peptides (LemTRP 1-9) isolated from the midgut and brain of the cockroach, Leucophaea maderae, all induced increases in spontaneous contractions of the L. maderae hindgut. Synthetic LemTRP 1 and 3-9, were equally potent in inducing contractions of the hindgut. More than seven of the nine C-terminal residues of the(More)
1. The neuropeptide proctolin (Arg-Tyr-Leu-Pro-Thr) both potentiates neurally evoked contractions and causes contractures of insect skeletal muscle. In the hindleg extensor tibiae muscle of the locust, Schistocerca gregaria, the proctolin analogue [Afb (p-NO2)2]-proctolin is also able to potentiate neurally evoked contractions but is approximately(More)
e appreciate the opportunity to respond to the thoughtful editorial regarding our studies investigating the efficacy and safety of vertebroplasty that were published recently in the New England Journal of Medicine. 1,2 The author of the editorial presents his personal anecdotal experience of successful outcomes of vertebroplasty as " evidence " that(More)
Nan may be re~radrlced without the ex~licit permission of the Executive Editor. Title: adapted from the evangelical hymn, "Blest be the Tie," by John Fawcett, 1740-1817, and the hymn's first line which reads in part, "Blest be the tie which binds Our hearts.. ." Footnotes have been left out after the pattern of Shelby Foote and others. A reference list has(More)
To explain the role of the Thr5 residue of proctolin (Arg-Tyr-Leu-Pro-Thr) in the myotropic activity of this insect neuropeptide, we synthesized two groups of its analogues: 1) Arg-Tyr-Leu-Pro-X-OH with X = Val (1), D-Val (2), Ile (3), D-Ile (4), Ala (5), D-Ala (6), Asn (7), Gln (8), Ser (9), Pro (10), Phe (11), Asp (12), Glu (13), Arg (14), D-Arg (15), Lys(More)
Proctolin caused dose-dependent (1-200 nM) contraction of the isolated hindgut of S. gregaria which was abolished by [alpha-methyl-L-tyrosine(2)]-proctolin (1 microM). In comparison, cycloproctolin (5 microM) reduced the proctolin maximum response by 41%. Hindgut homogenates contained [(3)H]proctolin binding sites with a K(d) value of 660 nM, a B(max) value(More)
The locust oviduct bioassay was used to assess a variety of proctolin analogues as possible agonists and antagonists of the peptide proctolin. Both [alpha-methyl-L-tyrosine2]proctolin and [N-methyl-L-tyrosine2] proctolin were antagonists of proctolin with thresholds of 5 x 10(-9) M. Interestingly, at these threshold doses the analogues were antagonists when(More)