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At least 343 records · Page 19Linked to original sources

PubMed1984

The in vitro generation of an antibacterial activity from the fat body and hemolymph of non-immunized larvae of Galleria mellonella.

A state of immunity in Galleria mellonella against the pathogen Pseudomonas aeruginosa is known to be induced by the injection of lipopolysaccharide (LPS), isolated from the homologous organism. An in vitro mixture of the LPS and whole or cell-free hemolymph from non-immunized larvae is not antibacterial. In vitro mixtures of fat body and cell-free hemolymph from non-immunized larvae, incubated at 25 degrees C for 20 hours generated a proteinaceous antibacterial activity. The generation of this activity was enhanced by the presence in the incubation mixture of LPS and/or hemocytes from non-immunized larvae. It is suggested that LPS causes the release of a hemocyte factor(s) which acts in conjunction with or directly on the fat body resulting in an enhanced production of antibacterial factors.

Animals↗

PubMed1987

A cobra venom factor (CVF)-induced C3 convertase activity in the hemolymph of Galleria mellonella.

A cobra venom factor (CVF)-induced C3 convertase has been generated from the hemolymph of Galleria mellonella. CVF was immobilized on Sepharose 4B and treated with cell-free hemolymph obtained from either unvaccinated G. mellonella larvae or larvae immunized with formalized Pseudomonas aeruginosa. The C3-cleaving activity was detected by the ability to cleave the alpha-chain of bovine C3 in a manner analogous to the CVF-induced mammalian C3 convertase, CVF,Bb. The insect-derived C3 convertase formed at 28 degrees C but not at 37 degrees C, then once formed was active at both 28 degrees C and 37 degrees C. EDTA did not inhibit the formation and action of the insect derived C3 cleaving activity.

Animals↗

PubMed1991

Characterization of a naturally occurring protease inhibitor in the hemolymph of the scorpion, Heterometrus bengalensis.

A protease inhibitor has been purified by ultracentrifugation, affinity chromatography on trypsin-sepharose 4B, and chromatofocusing on PBE-94 from hemolymph of the scorpion Heterometrus bengalensis. Homogeneity of the protease inhibitor was demonstrated by high performance liquid chromatography (HPLC). The protease inhibitor is a monomeric glycoprotein with a molecular weight of 120,000 dalton, which is stable between pH 4 and pH 8. The molecule inhibits serine proteases like trypsin and alpha-chymotrypsin and shows a noncompetitive mode of inhibition towards trypsin, with a Ki value of 6.1 x 10(-6) mM. Amino acid analysis shows a preponderance of aspartic acid, glutamic acid, serine, and glycine. The protease inhibitor is efficient in inhibiting phenoloxidase activity in both the hemolymph and the isolated phenoloxidase. Melanin synthesis by phenoloxidase may be influenced by this protease inhibitor.

Amino Acids↗

PubMed1988

The pneumostome rhythm in slugs: a response to dehydration controlled by hemolymph osmolality and peptide hormones.

1. One response of the terrestrial slug, Limax maximus to dehydration is the initiation and modulation of the pneumostome rhythm. When a slug has lost 15-20% of its initial body weight by evaporation, the frequency of pheumostome closures, which is less than 0.5 closures/min in fully hydrated slugs, begins to increase. 2. The frequency increases with further dehydration, but the average duration of each closure remains constant. Thus, the proportion of time during which the pneumostome is closed increases. Simultaneously, the area of the pneumostome opening decreases. 3. This behavior appears to be controlled in part by both the osmolality of the slug's hemolymph and by a peptide closely related to arginine vasotocin (AVT) and arginine vasopressin (AVP). Injecting intact slugs with mannitol, which increases the osmolality of the hemolymph, or with AVT or AVP, can initiate the pneumostome rhythm. 4. Mannitol injections, however, do not provoke the decrease in the area of the pneumostome opening which is induced by natural dehydration or by AVT or AVP injection. This suggests that at least two systems may be involved in the overall control of the pneumostome.

Animals↗

PubMed1975

The influence of hemolymph-binding protein on juvenile hormone stability and distribution in Manduca sexta fat body and imaginal discs in vitro.

The wing discs and fat body of Manduca sexta larvae contain enzymes (i.e. carboxylesterase and epoxide hydratase) that can convert the C18 juvenile hormone (JH) to the acid, diol and acid diol. No evidence of oxidative degradation was noted. In vitro studies suggest that JH can be compartmentalized within the cells of the fat body where it is less accessible to degradative mechanisms. Experiments utilizing a hemolymph-binding protein fraction (BPF) in vitro with fat body and imaginal discs indicate that the BPF retards the uptake of JH by tissues and its subsequent degradation by tissue enzymes. BPF also appears to protect JH from degradation by enzymes released into the medium. By these mechanisms the insect can maintain elevated JH titers for relatively long periods. Binding protein may also keep JH in solution in the hemolymph allowing its rapid distribution throughout the insect. The data suggest that the binding protein plays a key role in maintaining juvenile hormone titers.

Adipose Tissue↗

PubMedDate not supplied

Purification and characterization of a juvenile hormone binding protein from the hemolymph of the fourth instar tobacco hornworm, Manduca sexta.

A protein which binds the insect juvenile hormone has been isolated from the hemolymph of the fourth instar tobacco hornworm, Manduca sexta (Lepidoptera). Bioassay and chemical characterization of the bound ligand from the purified binding protein indicates that this molecule is the primary macromolecule responsible for juvenile hormone transport in the hemolymph of this insect. The juvenile hormone binding protein has been purified using gel filtration, ion exchange chromatography and preparative polyacrylamide gel electrophoresis. The protein is a single polypeptide chain of about 28,000 daltons with a sedimentation coefficient of 2.2S and an isoelectric point of 5.0. Binding analysis using a hydroxyapatite batch assay indicates that the juvenile hormone binding protein has one binding site with a Ka of 1.2 times 10(7) M-1 at 4 degrees C.

Animals↗

PubMed1990

Glycosylation and isoform variation of juvenile hormone esterase in the fat body and hemolymph during metamorphosis of Trichoplusia ni (Lepidoptera).

Two major isoforms of juvenile hormone esterase (JH esterase) from metamorphosing larvae of Trichoplusia ni were characterized with respect to isoform variation, glycosylation (lectin reactivity) and hormonal induction. Both forms are similarly inducible by juvenile hormone, and both become similarly glycosylated, as measured by concanavalin A binding. In prepupae, synthesis of new JH esterase from a low baseline and glycosylation within fat body are limiting steps in modulation of the level of JH esterase in the hemolymph. In contrast, during the pupal stage regulation of hemolymph JH esterase activity changes to a level other than synthesis of new enzyme or its glycosylation.

Animals↗

PubMed1984

Influence of octopamine on trehalase activity in muscle and hemolymph of the American cockroach, Periplaneta americana L.

Injection of adult male cockroaches (Periplaneta americana) with 10 microliter 1 microM octopamine causes elevated activity of trehalase (alpha, alpha-trehalose glucohydrolase; EC 3.2.1.28) in hemolymph and muscle but not in gut. Tyramine, dopamine and glutamate, at the same concentration, failed to elicit any effect on trehalase activity. Determination of some kinetic parameters for muscle and hemolymph trehalases reveal that octopamine causes an increase in Vmax without any significant alteration in the Km of the enzyme for trehalose. The results are discussed in terms of the physiological significance of octopamine-mediated activation of tissue trehalases.

Animals↗

PubMed1979

Demonstration of multiple forms of acid phosphatase in hemolymph of the African snail, Archachatina marginata.

1. Hemolymph from the giant African snail Archachatina marginata has been analyzed for its content of certain lysosomal hydrolases and shown to contain substantial quantities of acid phosphatase (285 units/ml) hexosaminidase (512 units per ml) and beta-glucuronidase (28 units/ml). 2. Hemolymph acid phosphatase can be fractionated into 6 active components by DEAE-Sephadex chromatography. 3. Some of the acid phosphatase species can be distinguished on the basis of heat stability, pH dependency and sensitivity to inhibitors including phosphate, L(+) tartrate, fluoride, formaldehyde and 1.10 phenanthroline.

Acid Phosphatase↗

PubMed1986

Antibacterial hemolymph proteins of Manduca sexta.

Exclusion column fractionated immune hemolymph of the M. sexta larva contains five peaks of anti-E. coli activity with molecular weights of greater than 140 kD and approximately 91, 54, 14 and 4 kD, plus one peak of lysozyme activity with a molecular weight of 17 kD. Purification of the 54 kD peak showed that this peak consists of the previously described M18 proteins which have monomeric weights of approximately 20 kD and had antibacterial activity against certain gram negative bacteria. Approximately 80% of the total hemolymph antibacterial activity was detected in the 14 and 4 kD peaks. These proteins, which kill both gram negative and gram positive bacteria, appeared to be directly analogous to the cecropins of H. cecropia. The greater than 140 and 91 kD peaks constituted only a minor part of the total antibacterial activity.

Animals↗

PubMed1992

Serine proteinase inhibitor profiles in the hemolymph of a wide range of insect species.

1. The inhibition of trypsin, chymotrypsin, neutrophil elastase and cathepsin G, and pancreatic elastase by the hemolymph of 14 insect species in six orders has been investigated. 2. All samples showed great diversity in terms of both total proteinase inhibitory capacity and specificity. 3. The highest total inhibitory capacity was found in the larval hemolymph of species in the beetle family Tenebrionidae and the lowest in that of an adult coreid bug, Acanthocephala femorata.

Amino Acid Sequence↗

PubMed1993

Atrial natriuretic peptides in the heart and hemolymph of the oyster, Crassostrea virginica: a comparison with vertebrates.

1. The content of atrial natriuretic peptides (ANPs) in the auricles of oysters, Crassostrea virginica, was significantly (P < 0.01) greater than in their ventricles. 2. High-performance gel permeation chromatography (HP-GPC) followed by ANF radioimmunoassay revealed two peaks in both oyster and vertebrate (rat) hearts--a major peak where the 12.6-14 kDa ANF prohormone elutes and a smaller peak where the pure human form of ANF elutes. 3. HP-GPC evaluation followed by proANF 31-67 radioimmunoassay revealed only an ANF-like prohormone while HP-GPC followed by proANF 1-30 radioimmunoassay revealed the ANF prohormone and a proANF 1-30-like peptide in oyster and rat hearts. 4. ANPs concentrations in hemolymph were 940 +/- 129, 225 +/- 25, and 100 +/- 10 pg/ml by the proANF 1-30, proANF 31-67, and ANF radioimmunoassays, respectively. 5. Atrial natriuretic-like peptides are present in the oyster heart in molecular species similar to vertebrate species and these peptides are also present in hemolymph.

Animals↗

PubMed1996

On the presence of prophenoloxidase in the hemolymph of the horseshoe crab, Limulus.

Melanization, and hence the participation of phenoloxidase, in defense mechanism of arthropods is well established. However, in the living fossil, horseshoe crab, it has been claimed that the prophenoloxidase system widely found in the hemolymph of most arthropods is absent. On the contrary, we present evidence for the presence of a prophenoloxidase system in the hemolymph of Limulus and a method to study its activation. Activation of prophenoloxidase was achieved by treatment with either the anionic detergent, SDS, or the cationic detergent, cetylpyridinium chloride. The detergents seemed to bind to the proenzyme below their critical micellar concentration and induce conformational changes that cause the activation of prophenoloxidase. In addition, a number of fatty acids and phospholipids also activated the prophenoloxidase. Proteases such as trypsin activated the enzyme only marginally. The approximate molecular weight of the proenzyme was found to be 70,000. Substrate specificity studies, product analysis and inhibition experiments revealed that the Limulus enzyme is a typical o-diphenoloxidase. The possible reasons for the failure to detect the phenoloxidase activity by earlier workers are discussed.

Animals↗

PubMed1983

Changes in hemolymph glucose, hepatopancreas glycogen, total carbohydrates, phosphorylase and amino transferases of sumithion-stressed freshwater rice-field crab (Oziotelphusa senex senex).

Adult crabs were exposed to 3 concentrations of sumithion with a control group over a 20-day period. Hemolymph glucose levels were monitored in each group over the course of the experiment. The group demonstrating the most acute and sustained hyperglycemia (2 ppm sumithion) was then analyzed, as also the controls for changes in hepatopancreas glycogen, total carbohydrates, phosphorylase and aminotransferases. Significant (P less than 0.001) depressions in hepatopancreas glycogen and total carbohydrates and elevations of phosphorylase and transaminases were observed in sumithion-stressed crabs when compared with controls. These changes are discussed with respect to gluconeogenesis and possible influences of hyperglycemic hormone, which is released into hemolymph of stressed crab.

Animals↗

PubMed1993

Paralytic peptides from hemolymph of the lepidopteran insect Trichoplusia ni Hubner.

1. Two paralytic peptides were isolated and identified from hemolymph of Trichoplusia ni Hubner. 2. These peptides cause rapid, rigid paralysis when injected into the lepidopteran insect, Manduca sexta. 3. The paralytic dose (ED50) of one peptide is 0.05 micrograms/g and the other is 0.9 micrograms/g. 4. Sequences are very similar to paralytic peptides from the hemolymph of other lepidopteran insects.

Amino Acid Sequence↗

PubMed1994

Lipopolysaccharide-lipophorin complex formation in insect hemolymph: a common pathway of lipopolysaccharide detoxification both in insects and in mammals.

The formation of the lipophorin-lipopolysaccharide (LPS) complex in Bombyx mori hemolymph and its role in LPS detoxification were explored. LPS, an antibacterial protein inducer in insects, was injected into B. mori larvae. Analytical density gradient ultracentrifugation revealed that after injection the LPS peak shifts to a zone of lower density with time. The shifted peak was identified as the lipophorin-LPS complex. This complex formation was also achieved in an in vitro mixture of cell-free hemolymph and LPS at 25 degrees C but not at 1 degree C. The lipophorin-LPS complex had a significantly lower capacity to elicit the mRNA of cecropin B, an antibacterial protein. The biological activity of reextracted LPS from the complex was slightly reduced in the Limulus test and no structural modification was observed in sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). These results suggested that the formation of lipophorin-LPS strikingly reduces the cecropin inducibility of LPS without any structural change in LPS. Similar serum lipoprotein-LPS complex formation and reduction of biological activities of LPS were also observed in mammals. We, therefore, suggest that the formation of the serum lipoprotein-LPS complex is a common pathway to inactivate LPS both in insects and in mammals.

Animals↗

PubMed2003

Trypanosoma rangeli uptakes the main lipoprotein from the hemolymph of its invertebrate host.

During its life cycle Trypanosoma rangeli crosses the hemolymph of its invertebrate host. In the present study, we demonstrate for the first time the uptake of lipophorin (Lp), the main lipid-transporting particle of insect hemolymph. We observed that living T. rangeli parasites uptake lipids from both 32P- and 3H-, or 125I-labeled Lp. However, the parasites do not uptake any other hemolymphatic protein such as 32P-labeled vitellogenin. The presence of a specific receptor to Lp in the parasite surface is suggested based on experiments using 125I-Lp. We also investigated the intracellular fate of lipids using Texas Red-labeled phosphatidylethanolamine-Lp. Parasites were observed under confocal microscope and displayed fluorescent-labeled lipids close to the flagellar pocket and in vesicles at the posterior region. In conclusion, this study raises a novel set of molecular events which takes place during vector-parasite interaction.

Animals↗

PubMed2005

Hemolymph coagulation and phenoloxidase in Drosophila larvae.

Hemolymph coagulation is a first response to wounding in insects. Although studies have been performed in large-bodied insects such as the moth Galleria mellonella, less is known about clotting in Drosophila melanogaster, the insect most useful for genetic and molecular analyses of innate immunity. Here we show the similarities between clots in Drosophila and Galleria by light- and electron microscopy. Phenoloxidase changes the Drosophila clot's physical properties through cross-linking and melanization, but it is not necessary for preliminary soft clot formation. Bacteria associate with the clot, but this alone does not necessarily kill them. The stage is now set for rapid advances in our understanding of insect hemolymph coagulation, its roles in immune defense and wound healing, and for a more comprehensive grasp of the insect immune system in general.

Animals↗