Juvenile Hormone
Mostrando 25-36 de 131 artigos, teses e dissertações.
-
25. Specificity of the juvenile hormone binding protein: The geometrical isomers of juvenile hormone I
The binding of the geometrical isomers (≥99% pure) of juvenile hormone I to the hemolymph juvenile hormone binding protein of Manduca sexta (Lepidoptera, Sphingidae) was analyzed. A technique is described for isomer separation by micropreparative high-resolution liquid chromatography. Analysis of competition was performed by using a “batch adsorption”
-
26. Effects of juvenile hormone and ecdysone on the timing of vitellogenin appearance in hemolymph of queen and worker pupae of Apis mellifera
The caste-specific regulation of vitellogenin synthesis in the honeybee represents a problem with many yet unresolved details. We carried out experiments to determine when levels of vitellogenin are first detected in hemolymph of female castes of Apis mellifera, and whether juvenile hormone and ecdysteroids modulate this process. Vitellogenin levels were mea
University of Arizona Library.
-
27. A Short Stereoselective Synthesis of Cecropia Juvenile Hormone. Experimental Details*
Experimental details are reported for a previously described synthesis of cecropia juvenile hormone.
-
28. Evolutionary Endocrinology of Juvenile Hormone Esterase in Gryllus Assimilis: Direct and Correlated Responses to Selection
Hemolymph juvenile hormone esterase (JHE) activity on the third day of the last stadium in the cricket, Gryllus assimilis, exhibited a significant response to selection in each of six replicate lines. Mean realized heritability was 0.26 +/- 0.04. The response was due to changes in whole-organism enzyme activity as well as to changes in the proportion of enzy
-
29. Juvenile hormone-binding protein from the cytosol of Drosophila Kc cells
Insect cells of an established line, Drosophila Kc cells, take up and metabolize juvenile hormone (JH). The cytoplasm of these cells contains a protein that binds JH with specificity, saturability, and high affinity (Kd = 1.56 × 10-8 M). The kinetics for the specific binding and dissociation of JH I were independently measured, and the rate constants were f
-
30. Prolactin is not a juvenile hormone in Xenopus laevis metamorphosis
Prolactin (PRL) is widely considered to be the juvenile hormone of anuran tadpoles and to counteract the effects of thyroid hormone (TH), the hormone that controls amphibian metamorphosis. This putative function was concluded mainly from experiments in which mammalian PRL was injected into tadpoles or added to cultured tadpole tissues. In this study, we show
The National Academy of Sciences.
-
31. Biosynthesis of the Juvenile Hormones of Manduca sexta: Labeling Pattern from Mevalonate, Propionate, and Acetate
Using organ culture, high-resolution liquid chromatography, and microchemical techniques, we demonstrated the efficient incorporation in vitro of several radiolabeled precursors into the two juvenile hormones of Manduca sexta. JH II, a homosesquiterpene hormone, reported from M. sexta as well as several other insects, incorporates radiolabel from acetate, me
-
32. Primary structure of four allatostatins: neuropeptide inhibitors of juvenile hormone synthesis.
Four neuropeptides that inhibit juvenile hormone synthesis by the corpora allata have been isolated from brains of the virgin female cockroach Diploptera punctata. These allatostatins are 8-13 amino acids long, are amidated, and show sequence similarity, including a 3-amino acid sequence at the C-terminal end that is common to all four peptides. The peptide
-
33. Transferrin in a cockroach: molecular cloning, characterization, and suppression by juvenile hormone.
In a study of juvenile hormone-regulated gene expression, we isolated an anonymous cDNA representing a message that was strongly suppressed by juvenile hormone in the fat body of the cockroach Blaberus discoidalis. The protein deduced from the cDNA sequence showed compelling resemblance in sequence to the transferrins, a superfamily of internally duplicated,
-
34. High specific activity enantiomerically enriched juvenile hormones: synthesis and binding assay.
A stereoselective total synthesis of chiral juvenile hormone I is described that allows stoichiometric introduction of two tritium atoms in the final step. Both optical antipodes of the pivotal epoxy alcohol intermediate were prepared in 95% enantiomeric excess by the Sharpless epoxidation of a (Z)-allylic alcohol. Elaboration of the hydroxy-methyl group to
-
35. Practical, Stereoselective Synthesis of Cecropia Juvenile Hormone
The high-yield, stereoselective conversion of geraniol (3,7-dimethyl-trans-2,6-octadien-1-ol) to the insect juvenile hormone, methyl 12,14-dihomojuvenate (methyl cis-10-epoxy-3,11-dimethyl-7-ethyl-trans, trans-2,6-tridecadienoate), has been performed by means of a nine-step route that avoids chromatography of intermediates.
-
36. Abnormal serum growth hormone response to exercise in juvenile diabetics
Groups of male nonobese juvenile diabetics with recent onset, short term (1-8 yr), and long-term (12-30 yr) diabetes as well as comparable nondiabetic controls were studied during exercise experiments. The chosen exercise load, 450 kg/min for 20 min never induced changes in serum growth hormone in our nondiabetic control subjects.