Comparative action of RH-0345 and pyriproxyfen on molting hormone production and protein analysis in mealworm pupae.
RH-0345 (halofenozide) was found to mimic the action of 20-hydroxyecdysone while pyriproxyfen was presented as a juvenile hormone analogue. In this study, RH-0345 (5, 10 micrograms/pupa) and pyriproxyfen (0.10 and 0.20 microgram/pupa), applied topically on newly ecdysed pupae of Tenebrio molitor, were investigated on ecdysteroid titers and hemolymph protein concentrations. During normal pupal development, the ecdysteroid titer measured using an enzyme immunoassay showed a single peak at day 3. The two compounds did not shifted the moment of the pupal ecdysteroid peak. However, RH-0345 at the highest dose (10 micrograms/pupa) increased the ecdysteroid titres recorded from the second day after topical application while pyriproxyfen decreased this hormonal production. In a second series of experiments, the compounds were evaluated on the protein concentrations in the hemolymph. In control pupae, change in protein concentrations showed two peaks. At a 5 micrograms dose, RH-0345 was found to reduce significantly the value of the first peak and at the highest dose, the first peak was not observed and the values recorded following treatment were significantly lower than in controls. Changes in protein concentrations showed that pyriproxyfen suppressed the second peak and the values recorded were either significantly increased at day 2 and 3, either reduced from day 4.
Aribi
N
N
Laboratoire de Biologie Animale Appliquée, Département de Biologie Université d'Annaba, 23000 Annaba, Algérie.
Lakbar
S
S
Smagghe
G
G
Soltani
N
N
D000818:Animals; D001565:Benzoates / Q000494:pharmacology*; D001798:Blood Proteins / Q000032:analysis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D026461:Ecdysteroids / Q000378:metabolism*; D006458:Hemolymph / Q000737:chemistry; D006834:Hydrazines / Q000494:pharmacology*; D019476:Insect Proteins / Q000032:analysis* / Q000187:drug effects; D007605:Juvenile Hormones / Q000494:pharmacology; D018978:Molting; D011679:Pupa; D011725:Pyridines / Q000494:pharmacology*; D013712:Tenebrio / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
D001565:Benzoates; D001798:Blood Proteins; D026461:Ecdysteroids; D006834:Hydrazines; D019476:Insect Proteins; D007605:Juvenile Hormones; D011725:Pyridines; C055613:pyriproxyfen; C437546:N-4-chlorobenzoyl-N'-benzoyl-N'-tert-butylhydrazine