THE MODULATORY EFFECT OF SCHISTOFLRFamide ON HEART AND SKELETAL MUSCLE IN THE LOCUST SCHISTOCERCA GREGARIA

摘要: SchistoFLRFamide (PDVDHVFLRFamide) is one of the endogenous FMRFamide-like neuropeptides found in nervous system locust Schistocerca gregaria (Robb et al. 1989; Robb and Evans, 1990). modulate actions a wide variety both skeletal visceral muscles insects (Evans Myers, 1986a; Schoofs 1993b) have been suggested to act as circulatory hormones locally released neurotransmitters (see discussion However, behavioural context(s) which such are at present unclear, although recent evidence suggests they may role feeding behaviour (Elia 1993). belongs subclasses insects, also includes leucomyosuppressin (pQDVDHVFLRFamide; Holman 1986), ManducaFLRFamide (pQDVVHSFLRFamide; Kingan 1990) TDVDHVFLRFamide Drosophila melanogaster (Nichols, 1992) Neobellieria bullata (Fonagy 1992). The sequence has Locusta migratoria (Schoofs 1993a). was originally isolated from using combination radioimmunoassay, HPLC bioassay Preliminary data indicate that it inhibits spontaneous contractions heart complex dose-dependent effect upon induced extensor tibiae muscle by stimulation slow excitatory motoneurone 1989). In addition, recently shown decrease amplitude frequency myogenic reduce basal tension oviduct (Peeff paper provides more detailed account modulatory on gregaria. effects synthetic peptide were measured semi-isolated (Cuthbert results expressed percentage change heartbeat its with respect measurements obtained immediately before application peptide. Measurements rate contraction averaged over 1 min period, starting (a) beginning pulse, (b) after start (c) 4 pulse (d) end pulse. bioactivity assayed another well-defined FMRFamide preparation locust. twitch evoked hindleg stimulating this Hz 1986b). maximal amplitude.