RESUMO
3-Hydroxyhexan-2-one (3-C6-ketol) has emerged as the most conserved pheromone structure within the beetle family Cerambycidae. In this study, we report the sex-specific production of this compound by males of 12 species of South American cerambycid beetles. Males of Chrysoprasis chalybea Redtenbacher and Mallosoma zonatum (Sahlberg) (Tribe Dichophyiini), and Ambonus lippus (Germar), Eurysthea hirta (Kirby), Pantonyssus nigriceps Bates, Stizocera plicicollis (Germar), and Stizocera tristis (Guérin-Méneville) (Elaphidiini) produced 3R-C6-ketol as a single component, whereas males of Neoclytus pusillus (Laporte & Gory) (Clytini), Aglaoschema concolor (Gounelle), Orthostoma abdominale (Gyllenhal) (Compsocerini), Dorcacerus barbatus (Olivier), and Retrachydes thoracicus thoracicus (Olivier) (Trachyderini) produced 3R-C6-ketol, along with lesser amounts of other compounds. In field trials testing 8 known cerambycid pheromone compounds, C. chalybea, E. hirta, and R. t. thoracicus were attracted in significant numbers to traps baited with 3-C6-ketol. A second field experiment provided support for the strategy of using the attraction of cerambycid species to test lures as a method of providing leads to their likely pheromone components. Because both sexes are attracted to these aggregation-sex pheromones, live beetles can be obtained from baited traps to verify they produce the compound(s) to which they were attracted, that is, that the compounds are indeed pheromone components.
Assuntos
Besouros , Animais , Masculino , Feminino , Hexanonas/farmacologia , Feromônios/farmacologia , Atrativos Sexuais/farmacologia , Especificidade da Espécie , América do SulRESUMO
Here, we study the pheromone chemistry of two South American cerambycid beetle species, and their behavioral responses to candidate pheromone components. Adult males of Stizocera phtisica Gounelle (subfamily Cerambycinae: tribe Elaphidiini) produced a sex-specific blend of (R)-3-hydroxyhexan-2-one with lesser amounts of 3-methylthiopropan-1-ol. In field bioassays, traps baited with racemic 3-hydroxyhexan-2-one and 3-methylthiopropan-1-ol did not catch conspecific beetles, but did catch both sexes of a sympatric species, Chydarteres dimidiatus dimidiatus (F.) (Cerambycinae: Trachyderini). We found that males of this species also produce (R)-3-hydroxyhexan-2-one and 3-methylthiopropan-1-ol, and small amounts of 2-phenylethanol. Subsequent bioassays with these compounds showed that a blend of 3-hydroxyhexan-2-one and 3-methylthiopropan-1-ol constitutes the aggregation-sex pheromone of C. d. dimidiatus, with 2-phenylethanol not influencing the attraction of conspecifics. During the field bioassays, six other species in the Cerambycinae also were caught in significant numbers, including Aglaoschema ventrale (Germar) (tribe Compsocerini), congeners Chrysoprasis aurigena (Germar), Chrysoprasis linearis Bates, and an unidentified Chrysoprasis species (Dichophyiini), and Cotyclytus curvatus (Germar) and Itaclytus olivaceus (Laporte & Gory) (both Clytini), suggesting that one or more of the compounds tested are also pheromone components for these species.
Assuntos
Besouros/efeitos dos fármacos , Feromônios/farmacologia , Animais , Besouros/fisiologia , Hexanonas/farmacologia , Masculino , América do Sul , Especificidade da EspécieRESUMO
The compound 1-(1H-pyrrol-2-yl)-1,2-propanedione ("pyrrole") is an important pheromone component of several Asian and South American species of longhorned beetles in the subfamily Cerambycinae. Here, we report the first confirmed identification of this compound as a pheromone component of a cerambycine species native to North America, the rare beetle Dryobius sexnotatus Linsley. Headspace volatiles from males contained (R)-3-hydroxyhexan-2-one and pyrrole (ratio 1:0.13), neither of which were detected in samples from a female. A field bioassay confirmed that adults of both sexes were attracted only to the binary blend of racemic 3-hydroxyhexan-2-one plus pyrrole, and not by either compound alone. Adults of another cerambycine, Xylotrechus colonus (F.), were attracted by 3-hydroxyhexan-2-one, consistent with this compound being the primary component of the pheromone of this species; attraction was not influenced by the presence of pyrrole. This study attests to the effectiveness of pheromone-baited traps in capturing rarely encountered species of cerambycids. It also provides further evidence that pyrrole represents another conserved pheromone motif within the Cerambycinae, now having been found in representatives of five cerambycid tribes from three continents.
Assuntos
Besouros/fisiologia , Atrativos Sexuais/farmacologia , Animais , Ásia , Feminino , Hexanonas/química , Hexanonas/farmacologia , Espécies Introduzidas , Masculino , Espectrometria de Massas , América do Norte , Pirróis/química , Pirróis/farmacologia , Atrativos Sexuais/química , Comportamento Sexual Animal/efeitos dos fármacos , América do SulRESUMO
Rats were treated with 2,5-hexanedione (2,5-HD) daily for 30 days. Hippocampal microslices were then incubated with [32P]phosphate and the in vitro rate of phosphorylation and the immuno-content of glial acidic fibrillary protein (GFAP) were measured. Exposure to 2,5-HD decreased by 25% the immuno-content of GFAP and increased by 35% its rate of phosphorylation, resulting in an increase of 88% in the ratio phosphorylation rate/immuno-content for this protein.
Assuntos
Reagentes de Ligações Cruzadas/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Hexanonas/farmacologia , Hipocampo/metabolismo , Animais , Autorradiografia , Feminino , Hipocampo/efeitos dos fármacos , Técnicas In Vitro , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Ratos , Ratos WistarRESUMO
Prolonged exposure to hexacarbon compounds is neurotoxic to humans and animals. As various hexacarbon compounds inhibit glycolytic enzymes in vitro, it has been suggested that this may underlie their neurotoxic effects in vivo. In the present investigation we examined whether long-term treatment with 2,5-hexanedione (200 mg/kg,sc) for 40 days affects the specific activity of brain and liver enolase, lactic dehydrogenase and malate dehydrogenase in female Wistar rats (150-170 g). Glycemia and liver glycogen levels were also determined. The specific activity of all enzymes tested, liver glycogen content and glycemia were not affected by chronic treatment with 2,5-hexanedione. Rats treated with 2,5-hexanedione weighed significantly less than control rats starting on day 18 of treatment (183 +/- 3.4 g for the vehicle group vs 171 +/- 3.2 g for the 2,5-hexanedione group). 2,5-Hexanedione also increased water intake (46% when compared to vehicle-treated rats). Prolonged treatment of rats with the non-neurotoxic hexacarbon 1,6-hexanediol (207 mg/kg, sc) significantly increased liver glycogen content (5.9 +/- 0.6 g/100 g for the vehicle group vs 9.0 +/- 1.1 g/100 g for the 1,6-hexanediol group) as well as food intake (44.0 +/- 1.5 g 100 g-1 6 days-1 for the vehicle vs 50.0 +/- 1.1 g 100 g-1 6 days-1 for the 1,6-hexanediol group).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Encéfalo/enzimologia , Glicólise , Hexanonas/farmacologia , L-Lactato Desidrogenase/metabolismo , Fígado/enzimologia , Malato Desidrogenase/metabolismo , Fosfopiruvato Hidratase/metabolismo , Animais , Glicemia/análise , Peso Corporal , Hexanonas/metabolismo , Glicogênio Hepático/análise , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
Hexacarbon compounds are neurotoxic to man and animals. These substances also inhibit various enzymes in vitro, including acetylcholinesterase. Since some cholinesterase inhibitors alter nociception we determined the effect of acute ip administration of 2,5-hexanedione on nociception in female Wistar rats (75-90 days old, 170-200 g; 15-17 rats in each group) using a tail-flick apparatus. The rats were injected ip with vehicle solution (120 mM NaCl containing 10 mM potassium phosphate buffer, pH 7.2) and 200, 400 or 800 mg/kg of 2,5-hexanedione in a volume of 1 ml/kg body weight. Tail-flick latencies were obtained 10, 30, 60 and 90 min after drug administration. All doses of 2,5-hexanedione caused antinociception (P less than 0.001) but the appearance and duration of the analgesia varied according to the dose of the drug. The highest dose tested (800 mg/kg) caused analgesia from 10 to 60 min, 400 mg/kg caused analgesia at 30 and 60 min, and 200 mg/kg produced antinociception only at 60 min after drug injection (P less than 0.05 for all the above comparisons). These results suggest that 2,5-hexanedione induces antinociception in rats. Whether this effect is mediated by a cholinergic mechanism is under investigation.
Assuntos
Analgesia , Hexanonas/farmacologia , Dor , Análise de Variância , Animais , Relação Dose-Resposta a Droga , Feminino , Hexanonas/administração & dosagem , Ratos , Ratos EndogâmicosRESUMO
Hexacarbon compounds are neurotxic to man and animals. These substance also inhibit various enzymes in vitro, including acetylcholinesterase. Since some cholinesterase inhibitor alter nociceptor we determined the effect of acute ip administration of 2,5-hexanedione on nociception in female Wistar rats (75-90 days old, 170-200g; 15-17 rats in each group) using a tail-flick apparatus. The rats were injected ip with vehicle solution (120mMNaCl containing 10 mM potassium phosphate buffer, pH 7.2) and 200, 400 or 800 mg/Kg of 2,5-hexanedione in a volume of 1 ml/Kg body weight. Tail-flick latencies were obtained 10, 30, 60 and 90 min after drug administration. All doses of 2,5-hexanedione caused antinociception (p<0.001) but the appearance and duration of the analgesia varied according to the dose of the drug. The highest dose tested (800 mg/Kg) caused analgesia from 10 to 60 min, 400 mg/Kg caused anal00 mg/Kg caused analgesia at 30 and 60 min, and 200 mg/Kg produced antinociception only at 60 min after drug injection (P < 0.05 for all the above comparisons). These results suggest that 2,5-hexanedione induces antinociception in rats. Whether this effect is mediated by a cholinergic mechanism is under inverstigation