PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Insect Hormones”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1975

Effect of insect hormones on RNA polymerases of mass-isolated imaginal discs of Drosophila melanogaster cultured in vitro.

Four chromatographically separable DNA-dependent RNA polymerases (nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) were partially purified from imaginal discs of Drosophila melanogaster. Their properties are similar to those described for RNA polymerases I and II isolated from other eukaryotes. In vitro incubation of discs with beta-ecdysone, juvenile hormone, or cycloheximide resulted in increased activity of RNA polymerase I. The increase was irreversible with beta-ecdysone incubation and removal but reversible with juvenile hormone incubation and removal. With beta-ecdysone, the rate of the increase in polymerase I activity paralleled the kinetics of ecdysone binding to discs and increases in the rate of precursor incorporation into RNA. A model to explain the increased acticity of RNA polymerase I is presented.

Amanitins↗
PubMed1992

Insect peptide hormones, an overview of the present literature.

A comprehensive overview of the recent state of the art of insect peptide hormones with chemical structures is presented. An increased interest in insect neuropeptides and dynamic development of that research area has been influenced by a rapid improvement of instrumentation necessary for isolation and structural characterization. Several research teams have studied the relationships between biological properties of insect and vertebrate peptide hormones. Thus hormones from the AKH family can be considered glucagon counterparts, whereas the myotropic hormones such as proctolin and Lem-PK (LPK) are a substance P equivalent. Insect melanization hormones Bom-MRCH in their structural characteristics and properties resemble those of mammal MSH, and leucosulfakinins Lem-SK-I and -II show some similarities with gastrin II and cholecystokinin. Bombyxin-II (Bom-PTTH-II) reveals a structural homology with human insulin and similar biological properties to adenocorticotropic mammal hormone. Allatostatin (Dip-JHS-I) may be compared to somatostatin as it can be inferred from the observations that this peptide modulates JH secretion in cockroach, Blattella germanica. Determination of the primary structure of eclosion hormones Mas-EH and Bom-EH-II as well as the amino acid sequence of allatotropin and allatostatin is a significant contribution to the understanding of the molecular mechanisms of metamorphosis and insect development.

Amino Acid Sequence↗
PubMed1978

The activity of insect juvenile hormone mimics in larval Amblyomma hebraeum Koch (Acarina: Metastriata: Ixodidae).

A total of 14 insect juvenile hormone mimics was tested for activity in Amblyomma hebraeum by exposing newly engorged larvae to filter paper impregnated with hormone mimics. The most active compounds used in this assay were HS 103 (6-ethyl-3-pyridyl geranyl ether; EC50=0,0018 mg/cm2), ZR 512 (Ethyl 3,7,11-trimethyldodeca-2,4-dienoate; EC50=0,0022 mg/cm2), HS 2 (6-methyl-3-pyridyl geranyl ether; EC50=0,0035 mg/cm2), ZR 615 (N-ethyl 3,7,11-trimethyldodeca-2,4-dieneamide; EC50=0,0035 mg/cm2), ZR 777 (Prop-2-ynyl 3,7,11-trimethyldodeca-2,4-dienoate; EC50=0,0039 mg/cm2) and ZR 515 (Isopropyl-11-methoxy 3,7,11-trimethyldodeca-2,4-dienoate; EC50=0,0094 mg/cm2). Activity in this assay was similar to that reported in insects and was consistent with the susceptibility of these compounds to metabolic inactivation. The results suggest that ZR 615 may be of possible use in tick control.

Animals↗
PubMed1990

Biosynthesis and degradation of the arginine-vasopressin-like insect diuretic hormone, a neurohormone in the migratory locust.

The migratory locust (Locusta migratoria) contains two neuropeptides structurally related to mammalian arginine-vasopressin: a 9-residue monomer, without known biological activity, and its antiparallel dimer: the arginine-vasopressin-like insect diuretic hormone which increases urine production at the Malpighian tubules level. We demonstrate hereunder that a transformation monomer-to-dimer-to a degradative product occurs in several steps. (1) A transformation monomer-to-dimer takes place in the suboesophageal ganglion, the site of biosynthesis of the monomer, obviously enzymatically controlled. (2) Monomer and dimer are simultaneously released from the suboesophageal ganglion into the haemolymph where the transformation monomer-to-dimer continues. (3) Dimer is then transported to its target-tissue, the Malpighian tubules, where it is degradated by another enzymatic process.

Animals↗
PubMed1992

Insecticidal properties of genetically engineered baculoviruses expressing an insect juvenile hormone esterase gene.

Exploring the possibility of enhancing the properties of baculoviruses as biological control agents of insect pests, we tested the effect of expressing an insect gene (jhe) encoding juvenile hormone esterase. Juvenile hormone esterase inactivates juvenile hormone, which regulates the outcome of an insect molt. A cDNA encoding the juvenile hormone esterase of Heliothis virescens was inserted into the genome of Autographa californica nuclear polyhedrosis virus such that the gene was expressed under the control of a strong, modified viral promoter. This virus, however, naturally encodes an ecdysteroid UDP-glucosyltransferase which inactivates ecdysone, the hormone which initiates molting. Since ecdysteroid UDP-glucosyltransferase could mask the effects of jhe expression by blocking molting entirely, jhe-expressing viruses in which the ecdysteroid UDP-glucosyltransferase gene was deleted or disrupted were constructed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of proteins from infected cells revealed several intracellular proteins and two major secreted proteins which reacted with antibodies to authentic juvenile hormone esterase. Western blot analysis coupled with tunicamycin treatment indicated that differential glycosylation was responsible for the multiple products. Hemolymph of recombinant virus-infected fourth-instar Trichoplusia ni larvae contained levels of juvenile hormone esterase activity 40-fold higher than maximal levels found in uninfected larvae. However, little or no difference in developmental characteristics, weight gain, or time of mortality was observed between insects infected with the jhe-expressing viruses and control viruses.

Animals↗
PubMed1975

Insect juvenile hormone mimics against the short-nosed cattle louse, Haematopinus eurysternus Denny (Anoplura), and their effect on warbles of Hypoderma sp. Latr. (Diptera:Oestridae).

Insect juvenile hormone mimics (IJH) at 0.1 and 0.01% were used as sprays for control of the short-nosed cattle louse, Haematopinus eurysternus Denny, on 11 heavily infested Hereford cows. A significant reduction of lice occurred although eradication was achieved in only one case. Severe reactions, apparently associated with the death or failure of complete development of cattle grub larvae, Hypoderma sp. Latr., were seen in the IJH-treated cows.

Animals↗