BACKGROUND: Adipokinetic hormones (AKHs) are insect neuropetides controlling stress situations including those elicited by insecticide treatment. The effect of Pyrap-AKH on the mortality of the firebug Pyrrhocoris apterus (L.) treated with the insecticide permethrin (Ambush 25 EC) was studied. RESULTS: Coinjection of 50 ng permethrin with 80 pmol Pyrap-AKH induced a significant 2.3-fold increase in bug mortality compared with the insecticide alone. The results were confirmed by topical coapplication of both agents (400 ng and 80 pmol respectively). Injections of 50 and 100 ng permethrin elicited a significant increase in the AKH level in CNS and the haemolymph. The results indicate an involvement of AKH in stress response to permethrin. The enhanced effect of insecticide by AKH treatments probably results from the stimulatory role in bug metabolism: carbon dioxide production was increased 3.5- and 2.5-fold respectively 1 and 3 h after permethrin treatment, and 4.3- and 3.4-fold after the permethrin plus AKH cotreatment, compared with the control. CONCLUSION: The elevation of metabolism could intensify the permethrin action by its faster penetration into tissues and by stimulation of biochemically active cells, and could be a reason for enhanced action of permethrin after its cotreatment with Pyrap-AKH.
- MeSH
- centrální nervový systém účinky léků metabolismus MeSH
- fyziologický stres účinky léků MeSH
- hemolymfa metabolismus MeSH
- Heteroptera účinky léků metabolismus fyziologie MeSH
- hmyzí hormony krev metabolismus farmakologie MeSH
- insekticidy aplikace a dávkování MeSH
- kyselina pyrrolidonkarboxylová analogy a deriváty krev metabolismus farmakologie MeSH
- oligopeptidy krev metabolismus farmakologie MeSH
- oxid uhličitý metabolismus MeSH
- permethrin aplikace a dávkování MeSH
- pesticidoví synergisté krev metabolismus farmakologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The diacylglycerols (DG) molecular species and their fatty acid (FA) composition were investigated by electrospray mass spectrometry (ESI-MS) and by gas chromatography with flame ionisation detection (GC-FID) in haemolymph of Locusta migratoria after application of adipokinetic hormones Locmi-AKH-I, -II and -III. The analyses showed (1) a heterogeneous distribution of individual DGs in haemolymph after the hormone application. The results revealed that mobilization of the DGs is molecular species-specific with the highest proportion of 34:1 DG (16:0/18:1 - mw 594Da) for all Locmi-AKHs bearing palmitic acid (C16:0) and oleic acid (C18:1) residues, and forming about 20% of the total mobilized DG content. (2) Analysis of fat body triacylglycerols revealed that all Locmi-AKHs mobilize the DGs selectively with the preference of those possessing the C18 and C16 FAs. The fat body FAs with carbon chain longer than 18 did not participate in the mobilization. (3) A distribution of FAs in the DG structures obtained by LC/ESI-MS, and FA analysis by GC-FID after transmethylation indicated a certain degree of Locmi-AKH selectivity toward the mobilized DGs and hence the FAs. The Locmi-AKH-I significantly prefers mobilization of DGs containing unsaturated FAs, while Locmi-AKH-II and -III prefer mobilization of saturated FAs.
- MeSH
- diglyceridy metabolismus MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
- hmyzí hormony metabolismus MeSH
- hmyzí proteiny metabolismus MeSH
- kyselina pyrrolidonkarboxylová analogy a deriváty metabolismus MeSH
- Locusta migratoria metabolismus MeSH
- oligopeptidy metabolismus MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
