Newly discovered functions for some myotropic neuropeptides in locusts☆

Effect of corazonin and crustacean cardioactive peptide on heartbeat in the adult American cockroach (Periplaneta americana)

“…New aspects in this respect emerged when it was found that [His 7 ]-corazonin could induce dark body coloration in the white, albino strain of the locust (Tanaka, 2000(Tanaka, , 2001Tanaka et al, 2003;Yerushalmi et al, 2002;Grach et al, 2003). These darkening effects on the cuticular pigmentation, together with the effects on acceleration of egg development and influence on phase transition in locusts (Schoofs et al, 2001;Hoste et al, 2002;Breuer et al, 2003), have the character of true in vivo or physiological effects of corazonin. A similar situation occurs in the case of the reduced rate of spinning in larvae of Bombyx or induction of preecdysis and ecdysis behavior in the pharate larvae of Manduca (Kim et al, 2004).…”

The effect of corazonin on heartbeat reversal in pupae of the tobacco hornworm, Manduca sexta (Lepidoptera: Sphingidae)

“…Accordingly, the principal neurohaemal organ of insects, the corpus cardiacum, is often expected to liberate dozens of different peptidic neurohormones, which ought to be quickly destroyed or inactivated by aminopeptidase enzymes of the haemolymph (cf. Quistad et al, 1984;Predel, 2001;Schoofs et al, 2001;Nachman et al, 2002;Audsley & Weaver, 2003;Roller et al, 2003). Professional biologists are astonished by the enormous progress in chemical synthesis and methods of peptide analysis.…”

“…Advanced MALDI-TOF mass spectrometric (Predel, 2001;Audsley & Weaver, 2003) and immunocytochemical techniques (Roller at al., 2003) enabled identification of neuropeptide molecules not only in the corpora cardiaca, but also within the separate neurosecretory cells of the brain. According to Schoofs et al (2001), structural information was available in 2001 for more than 60 peptides only in locusts. Biological activity of these peptides was usually estimated by in vitro assays, based on the increased contractions of the visceral muscles.…”

“…The darkening effects on the cuticle produced by oily injections of corazonin (and some other peptides; see Yerushalmi et al, 2002), suggested the possible existence of true, in vivo, effects of the peptide. The in vivo effects of corazonin were further extended to acceleration of egg development and inhibition of food intake in locusts (Schoofs et al, 2001), reduced rate of spinning in silkworm larvae , or influence on the phase transition in locusts (Hoste et al, 2002;Breuer et al, 2003;Rahman et al, 2003).…”

Distribution of Short Neuropeptide F-like Immunohistochemical Reactivity in the Brain and Midgut of the Terrestrial Isopod, <i>Armadillidium vulgare</i> (Latreille)

“…In the silk worm, Bombyx, it has been suggested that sNPF regulates hormone release and regulate JH synthesis along with allatotropin [15,16]. In the locust, it affected the synthesis of vitellogenin via juvenile hormone (JH) synthesis [17] and stimulated ovarian development [6,18]. sNPF has also been implicated in the regulation of feeding behavior in D. melanogaster [19].…”