The stimulation of oogenesis inPieris brassicae by the juvenile hormone derivative farnesenic acid ethyl ester

Zusammenfassung Das synthetische Juvenilhormonderivat Farnesensäuräthylester stimuliert die Eireifung in decapitierten virginen Weibchen vonPieris brassicae. Da die Eireifung dieser Art normalerweise durch aktive Corpora allata stimuliert wird, darf angenommen werden, dass der gonadotrope Effekt der Corpora allata auch in Lepidopteren auf der Produktion von Juvenilhormon beruht.     

On the biosynthesis of biliverdin-IXγ inPieris brassicae

Zusammenfassung Radioaktiv markiertes Glyzin wird von Raupen des Kohlweisslings (Pieris brassicae) in Biliverdin-IX (Pterobilin), nicht jedoch in die gleichfalls aus dem Tegument isolierten Phäophorbide eingebaut. Die Aktivitätsverteilung in den Abbauprodukten IIIb und IV zeigt, dass dieser Einbau entsprechend dem «normalen» Biosyntheseweg für Gallenfarbstoffe erfolgt.     

Effect of diet on response to juvenile hormone inGalleria mellonella larvae

Zusammenfassung Mit Juvenilhormon und JH-Derivaten injizerte Larven der WachsmotteGalleria mellonella zeigten stärkere morphogenetische Effekte, wenn ihre Nahrung Bienenwachs entheilt, als wenn diese fehlt.     

Tissue distribution of juvenile hormone hydrolytic activity inGalleria mellonella larvae

Summary Juvenile hormone (JH) hydrolytic activity was determined in different tissues of day-4 last instar larva ofGalleria mellonella. Midgut, gonad, imaginal wing discs and fat body contain higher JH hydrolytic activity than hemolymph, while silk gland and body wall have lower activity. JH esterase activity in imaginal wing discs exhibits a pattern of age-related changes different from that of the hemolymph.We acknowledge the support of this research by the National Institutes of Health (GM 22429) and the Johnson Wax Foundation. Address to which reprint requests may be sent.     

Occurrence of monocentric chromosomes inPieris brassicae L. (Lepidoptera,Pieridae)

Summary Monocentric chromosomes with localized kinetochores were obtained inPieris brassicae (Lepidoptera, Pieridae) by using colchicine treatment and air-drying method.We wish to express our thanks to Dr A.K. Datta-Gupta, Professor and Head of our Department for providing the research facilities and for encouragement.     

The effects of juvenile hormone analogues on the eggs ofPieris brassicae L.

Summary Mortality was produced in the eggs ofP. brassicae after treatment with 3 juvenile hormone analogues. The mortality was greatest in the early stages of embryonic development.I am grateful to the United Kingdom Ministry of Agriculture, Fisheries and Food, who provided a Research Studentship for this work.     

Reversal of spinning behavior in last instar larvae ofPieris brassicae treated with juvenile hormone derivatives

Zusammenfassung Werden Raupen des KohlweisslingsPieris brassicae im letzten Stadium mit synthetischen Juvenilhormonderivaten behandelt, so zeigen sie vor der nächsten Häutung, je nach Hormonspiegel, entweder das füri eine Puppen- oder für eine Larvenhäutung charakteristische Verhalten. In Insekten, deren Nervensystem bereits teilweise präpupal determiniert ist, kann eine hoher Hormonspiegel eine Umkehr vom ontogenetisch späteren Präpupalverhalten zur ontogenetish früheren Stufe des typischen Larvalverhaltens induzieren.

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The author thanks Hoffmann-La Roche Ltd., Basel for samples of the substances.     

Juvenile hormone titers in penultimate and last instar larvae ofPieris brassicae andBarathra brassicae,in relation to the effect of juvenoid application

Summary JH titer was determined in the haemolymph of penultimate and last instar larvae ofPieris brassicae L. andBarathra brassicae L. The differences we observed were consistent with physiological differences between the two species.The authors feel indebted to Prof.V. J. Brookes for useful comments.     

Reversible juvenile hormone inhibition of ecdysteroid and juvenile hormone synthesis by the ring gland ofDrosophila melanogaster

Juvenile hormone bisepoxide (JHB₃) and juvenile hormone III (JH III) both inhibited the in vitro production of ecdysteroids by ring glands and brain-ring gland complexes from third instar post-feeding larvae ofDrosophila melanogaster in a reversible manner, although JHB₃ had greater efficacy. The JH III and JHB₃ precursor, methyl farnesoate, did not affect ecdysteroid production. The in vitro synthesis of total detectable JH (JHB₃+JH III+methyl farnesoate) by the corpus allatum portion of the isolated ring gland was also inhibited reversibly in the presence of exogenous JHB₃ and JH III, but not by methyl farnesoate. These data indicating negative feedback are in agreement with the accepted dogma of endocrine gland regulation.     

Reversible juvenile hormone inhibition of ecdysteroid and juvenile hormone synthesis by the ring gland of Drosophila melanogaster

Juvenile hormone bisepoxide (JHB3) and juvenile hormone III (JH III) both inhibited the in vitro production of ecdysteroids by ring glands and brain-ring gland complexes from third instar post-feeding larvae of Drosophila melanogaster in a reversible manner, although JHB3 had greater efficacy. The JH III and JHB3 precursor, methyl farnesoate, did not affect ecdysteroid production. The in vitro synthesis of total detectable JH (JHB3 + JH III + methyl farnesoate) by the corpus allatum portion of the isolated ring gland was also inhibited reversibly in the presence of exogenous JHB3 and JH III, but not by methyl farnesoate. These data indicating negative feedback are in agreement with the accepted dogma of endocrine gland regulation.     

Juvenilizing effect of ecdysone mimic RH 5849 inGalleria mellonella larvae

The response of the final instar larvae ofG. mellonella to topical application of the non-steroidal ecdysone mimic, RH 5849, was age-related as well as dose-dependent. In young final instar larvae, moderate doses of RH 5849 induced perfect supernumerary larval moults, but doses equal to and higher than 8.5 μg per larva caused premature formation of larval cuticle and were lethal. Application of RH 5849 significantly increased allatotropic activity of the brain, and also activated synthesis of juvenile hormone (JH) by the corpora cardiaca/corpora allata complex. Simultaneous application of RH 5849 and FMev, a potent inhibitor of JH synthesis, to young final instar larvae lowered the incidence of perfect supernumerary larval moults. We conclude that the effect of RH 5849 on the developmental programme inG. mellonella is mediated by the corpora allata.     

Forced synthesis of trace amounts of juvenile hormone II from propionate by corpora allata of a juvenile hormone III-producing insect

Summary Corpora allata of the cockroachDiploptera punctata normally synthesize only the isoprenoid juvenile hormone III (JH III). Only under extreme in vitro conditions (absence of carbon sources other than propionate) do they produce trace amounts of the homoisoprenoid JH II in addition to JH III. The specificity of the in vitro synthesis of JH III byD. punctata is thus consistent with the observed lack of homoisoprenoid JHs in this insect.     

Forced synthesis of trace amounts of juvenile hormone II from propionate by corpora allata of a juvenile hormone III-producing insect

Corpora allata of the cockroach Diploptera punctata normally synthesize only the isoprenoid juvenile hormone III (JH III). Only under extreme in vitro conditions (absence of carbon sources other than propionate) do they produce trace amounts of the homoisoprenoid JH II in addition to JH III. The specificity of the in vitro synthesis of JH III by D. punctata is thus consistent with the observed lack of homoisoprenoid JHs in this insect.     

Failure of amantadine to modify serum growth hormone and insulin levels

Riassunto In sei volontari normali, la somministrazione acuta, sia orale che e.v. di 300 mg di amantadina non ha causato modificazioni dei livelli serici di GH. Anche i valori di insulinemia, glicemia e di FFA plasmatici non hanno subito variazioni.     

Specificity of binding of juvenile hormone III to hemolymph proteins ofLeptinotarsa decemlineata andLocusta migratoria

Summary Binding specificity of juvenile hormone (JH) III enantiomers and analogs to hemolymph proteins ofLeptinotarsa decemlineata andLocusta migratoria was investigated by competitive displacement tests. The order of binding affinity was 10R-JH-III>10R, 10S-JH-III10S JH-III> methylfarnesoate for analogs of the epoxide group and diazo-JHA-IV>EFDA for analogs of the methylester. Both the epoxide and ester groups are important for the interaction of JH-III with its binding protein.18 November 1986     

Failure to demonstrate a functional connection between the adrenal gland and ventromedial hypothalamic nuclei with regard to control of food intake

Zusammenfassung Die vonHalasz undSzentagothai gezeigte funktionelle Beziehung der Nebennierenrinde mit dem N. ventromedialis hypothalami legte die Vermutung nahe, dass möglicherweise diese Kerne die Futteraufnahme kontrollieren und durch Nebennierenentkernung beeinflusst werden können. Nach unseren Ergebnissen bei jungen, weiblichen Ratten ist dies sicher nicht der Fall. Auch die erhöhte Futteraufnahme normaler Ratten, welche durch Läsionen in den ventromedialen Kernen hervorgerufen werden kann, blieb durch Enukleierung der Nebenniere unbeeinflusst.

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This investigation was supported by a research grant (H-6975) from the National Heart Institute of the National Institutes of Health, U.S. Public Health Service.