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1. Activation of fat body in Periplaneta americana (Blattoptera: Blattidae) by hypertrehalosemic hormones (HTH): New insights into the mechanism of cell signalling

Creator:
Steele, John E.
Format:
print, text, and regular print
Type:
article, bibliography, model:article, and TEXT
Subject:
zoologie, entomologie, hmyz, Blattoptera, Blattidae, Periplaneta americana, hemolymfa, trehalosa, biosyntéza, kontrola biosyntézy, hypertrehalosemické hormony, mechanismus účinku, 595.2/.7, and 591.1
Language:
English
Description:
In cockroaches and certain other insects the concentration of trehalose in the hemolymph is increased by hypertrehalosemic hormone (HTH), a neuropeptide originating in the corpus cardiacum. A vital step in the action of HTH to promote conversion of glycogen stored in the fat body to trehalose is the activation of phosphorylase. The means by which HTH activates phosphorylase, with particular emphasis on its role in the regulation of intracellular calcium, is discussed. Additional information supporting the view that HTH stimulated synthesis of trehalose, and possibly its release from the trophocyte, is regulated by fatty acids and eicosanoids is presented., John E. Steele, and Lit
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2. Evolution and function of the insect hexamerins

Creator:
Burmester, Thorsten
Format:
print, text, and regular print
Type:
article, bibliography, model:article, and TEXT
Subject:
zoologie, hmyz, hemolymfa, bílkoviny, hexameriny, funkce, evoluce, 595.2/.7, and 591.3
Language:
English
Description:
Hexamerins are hemocyanin-related haemolymph proteins that are widespread in insects and may accumulate to extraordinarily high concentrations in larval stages. Hexamerins were originally described as storage proteins that provide amino acids and energy for non-feeding periods. However, in recent years other specific functions like cuticle formation, transport of hormones and other organic compounds, or humoral immune defense have been proposed. During evolution, hexamerins diversified according to the divergence of the insect orders. Within the orders, there is a notable structural diversification of these proteins, which probably reflects specific functions. In this paper, the different possible roles of the hexamerins are reviewed and discussed in the context of hexamerin phylogeny., Thorsten Burmester, and Lit
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3. Flight substrates in blister beetles (Coleoptera: Meloidae) and their regulation by neuropeptides of the AKH/RPCH family

Creator:
Gäde, Gerd and Auerswald, Lutz
Format:
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Type:
article, bibliography, model:article, and TEXT
Subject:
zoologie, entomologie, hmyz, brouci, Meloidae, Decapotoma lunata, Mylabris oculata, let, letové substráty, hemolymfa, tuky, cukry, proline, koncentrace, regulace koncentrace substrátů, neuropeptidy, AKH/RPCH neuropeptidy, 595.2/.7, and 591.1
Language:
English
Description:
We measured energy substrates in haemolymph and flight muscles of the large blister beetle Mylabris oculata at rest and after tethered, lift-generating flight. Flight of 1 min duration at an ambient temperature of 38-42°C did not effect a change in the concentration of lipids in the haemolymph, whereas a small, significant decrease in the concentrations of carbohydrates and a 3-fold larger one in the levels of proline were noted, as well as a concomitant increase in alanine. In the flight muscles, glycogen and proline concentrations were diminished slightly but significantly upon flight, whereas alanine levels were increased. Two hours of rest after a flight of 1 min completely reversed the metabolic situation in haemolymph and flight muscles to pre-flight levels. We could isolate two neuropeptides from the corpora cardiaca of M. oculata, which by retention time and mass analyses are characterised as the decapeptide Del-CC (pGlu-Leu-Asn-Phe-Ser-Pro-Asn-Trp-Gly-Asn-NH2) and the octapeptide Tem-HrTH (pGlu-Leu-Asn-PheSer-Pro-Asn-Trp-NH2) previously fully identified from the corpora cardiaca of the blister beetle, Decapotoma lunata (Gäde, 1995). Subsequently, it was unequivocally demonstrated that low doses of Del-CC and Tem-HrTH elicited increases in the concentration of proline and carbohydrates in the haemolymph of D. lunata and M. oculata, but did not change the concentration of lipids in both species. In conclusion, the two endogenous peptides are hypertrehalosaemic and hyperprolinaemic, thus very likely regulating the mobilisation of the two important flight substrates of blister beetles, namely carbohydrates and proline., Gerd Gäde, Lutz Auerswald, and Lit
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public