Benzoquinones of the Beetles,Tribolium Castaneum Tribolium Confusum

Abstract

Tribolium castaneum T. confusum were washed in HPLC-grade methanol, and the methanolic washes were analyzed by UV spectroscopy, reversed phase HPLC, and GC/MS. The methanolic washes from both species contained methyl-1,4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ). The amounts of MBQ recovered from the two species were not significantly different, but the amounts of EBQ and total benzoquinones (MBQ + EBQ) recovered from T. castaneum were significantly greater than for those recovered from T. confusum. The methods described are superior to previous methods for isolating, identifying, and quantifying the benzoquinones in these beetles, since they are relatively simple, fast, do not require handling of the beetles, and are sensitive enough to quantify the benzoquinones of a single beetle.     

Copper toxicity and adaptation in the marine diatom Ditylum brightwellii

• 1.1. The planktonic diatom Ditylum brightwellii, grown in light-limited resp. nitrogen-limited continuous culture, has been exposed to Cu levels, comparable with those in the Scheldt estuary.
• 2.2. At increasing levels D. brightwellii initially detoxified Cu, producing metal-binding ligands (amino acids), and increasing its cell volume.
• 3.3. In light-limited D. brightwellii, photosynthesis could be adjusted to increasing Cu stress, division rates remained constant, and cells proved to be adaptable to 200 nM dissolved Cu.
• 4.4. Nitrogen-limited D. brightwellii detoxified Cu inadequately: it stored large amounts of Cu (30–60 μM) that inhibited cell division.

     

Effects of recombinant salmon growth hormone on hypophysectomized male Fundulus heteroclitus

• 1.1. Recombinant salmon growth hormone at doses of 0.8 and 2.1 μg/g significantly enhanced linear growth in hypophysectomized male killifish, Fundulus heteroclitus, over that of controls and a significant regression was found between growth and the logarithm of dose.
• 2.2. Bovine growth hormone elicited significant growth enhancement at all three dosages tested (1,4 and 10 μg/g) and a significant log/dose relationship was also observed.
• 3.3. Observations on the relative weight of the gonads indicate that whole salmon pituitary extract (25 μg/g) possesses strong gonadotropic activity and that both bGH and rsGH had smaller but significant effects on the gonads.
• 4.4. It is suggested that growth hormone may play a subsidiary synergistic role to other pituitary hormones in gonadal development.

     

Direct calorific heat equivalent of oxygen respiration in the egg of the flour beetle Tribolium confusum (coleoptera: Tenebrionidae)

• 1.1. Directly determined heats of embryogenesis were measured for Tribolium confusum eggs in a microcalorimeter fitted with air exchange, at 30°C.
• 2.2. Parallel oxygen uptake measurements were made at 30°C, and combined with the heats to give the Calorific Equivalent of Oxygen Respiration quotient (the C.O.R.).
• 3.3. The average C.O.R. values for the eggs in the 70 hr interval before hatch was 3.6 ± 0.2 kcal/l O₂. This is somewhat lower than other (e.g. homoiothermic vertebrate) tissue. The C.O.R. increases to large values, in excess of 5 kcal/l O₂ after hatch.
• 4.4. The specific heat production during embryogenesis was 0.43 × 10⁻⁶cal/sec per mg live weight.

     

Cardiac responses of larval and adult tiger salamanders to submergence and emergence

• 1.1. The ECG of aquatic Amhystoma tigrinum from the Colorado Rocky Mountains was recorded while the animals submerged and emerged in water. Older larvae and metamorphosed adults were compared.
• 2.2. Free-swimming animals of both types showed slight emergence tachycardia when taking a “gulp” of air.
• 3.3. Preventing access to air for 30 min or more resulted in a slight bradycardia in larvae. Some adults responded with increased, others with decreased, heart rate depending on their level of excitement.
• 4.4. Restraining the animals before forced submergence caused a greater bradycardia than when unrestrained.
• 5.5. Low dissolved oxygen accentuated the cardiac responses of larvae to submergence but not in adults.
• 6.6. Atropine only partially blocked the diving responses of both forms.
• 7.7. The degree of submergence bradycardia seems to be a function of the ability to extract oxygen from water. It probably is not an adaptation to diving in these forms. Instead the submerged heart rate in these predominantly aquatic salamanders may be the “normal” rate with emergence tachycardias for breaths of air.

     

Characterization and purification of biliverdin reductase from the liver of eel,Anguilla japonica

• 1.1. Biliverdin reductase from the liver of eel, Anguilla japonica was characterized and purified with a novel enzymatic staining method on polyacrylamide electrophoretic gel.
• 2.2. This enzyme could use both NADPH and NADH as coenzyme. The K_m of NADPH was 5.2 μM, while that of NADH was 5.50 μM.
• 3.3. The optimum reaction pH for using HADPH as coenzyme was 5.3. That for NADH was 6.1. The optimum reaction temperature is 37°C.
• 4.4. When NADPH was used as coenzyme, the K_m of biliverdin was 0.6 μM. When NADH was used as coenzyme, the K_m of biliverdin was 7.0 μM.
• 5.5. The activity of the enzyme was inhibited by the concentration of biliverdin. Also, the potency of the enzyme was much less than that of the analogous enzyme isolated from mammals.
• 6.6. This is a fairly stable enzyme with a mol. wt around 67,000. Its estimated pI was pH 3.5–4.0.
• 7.7. This is the first time biliverdin reductase has been isolated and characterized from a vertebrate other than mammals. The property of it is quite different from that of mammals.

     

Partial purification of rat liver cytoplasmic acetyl-CoA synthetase; Characterization of some properties

• 1.1. Rat liver cytoplasmic acetyl-CoA synthetase was partially purified (purification factor = 23, yield = 30%).
• 2.2. The apparent K_ms for acetate, coenzyme A, ATP and MgCl₂ were determined and found to be 52.5 μM, 50.5 μM, 570 μM and 1.5 mM, respectively.
• 3.3. The partially-purified enzyme showed a low affinity for short-chain carbon substrates other than acetate.
• 4.4. The properties of the partially-purified enzyme were compared with those of enzymes from other sources.

     

Inhibition of tubifex pyruvate kinase by storage phosphagens and adenosine triphosphate

• 1.1. Within the first 6–12 hr of experimental anaerobiosis the concentration of Tubifex phosphagens, phospholombricine and phosphoarginine, decrease to 10–30% of the values under aerobic conditions (7.5 and 3. μM/g dry wt).
• 2.2. High concentrations of both phosphagens (5–25 mM) inhibit Tubifex pyruvate kinase (PK) activity, the inhibitory mechanisms seem to be different. The inhibition is not mediated by the corresponding phosphagen kinases. Inhibition by phosphoarginine obviously requires an additional factor, which chemical nature is still unknown.
• 3.3. Certain phosphocreatine preparations also inhibit Tubifex PK. This inhibition, however, is likely due to contaminants than to phosphocreatine.
• 4.4. Mg-ATP demonstrates the strongest inhibitory effect on PK activity with a mixed competitive inhibition vs PEP and a non competitive vs ADP.

     

The inhibitory effect of tetramethylethylene diamine on water soluble and membrane bound acetylcholinesterase activity

• 1.1. The inhibitory effect of N,N,N′,N′-tetramethylethylene diamine (TEMED) on water soluble (WSAChE) and membrane bound (MBAChE) acetylcholinesterase was investigated.
• 2.2. TEMED (0.5–4.0 mM) reversibly inhibited WSAChE activity (18–62%) and MBAChE (20–61%) in a concentration dependent manner.
• 3.3. The IC₅₀ being about 2.8 mM for WSAChE and 2.6 mM for MBAChE.
• 4.4. Lineweaver-Burk plots indicated that the nature of inhibition is noncompetitive for both water soluble and membrane bound acetylcholinesterase, with K_m values 68 μM and 123 μM respectively.
• 5.5. An Arrhenius plot showed that the transition temperature (TT) is unaffected in the presence of TEMED.
• 6.6. The activation energy was increased below and above TT in the case of WSAChE only.
• 7.7. On the basis of this behaviour of TEMED with AChE. it can be proposed that it can be used as an eluting agent for the bounded AChE to affinity ligand and may have beneficial action on the reactivatability of irreversibly-inhibited AChE due to its structure.
• 8.8. Moreover there is a possibility that it can be used as a therapeutic agent for the treatment of Alzheimer's disease, myasthenia gravia and glaucoma like some other inhibitors of AChE.

     

Relationship between anal intake of water and anal rhythm in the crayfish

• 1.1. Water flux through the anus is seen in Procambarus clarkii and it ceases on ablation of the 6AG.
• 2.2. The quantity of anal water flux (volume per 30 min or 5 min) accompanying spontaneous or passive anal contractions is measured by connecting polyethylene tubing to the intestine.
• 3.3. The quantity is proved not to be affected by the anal rhythm, defaecation or gastroliths in the stomach. But it will be subjected to synchronizing movements of the hindgut to anal rhythm.
• 4.4. The anterior intestinal nerve is assumed to contribute to anal water flux, but the anal motoneurones and the command interneurone are not so.
• 5.5. Compared the quantity accompanying spontaneous anal contractions (16.05 ± 24.04 μl/30 min, n = 18) with the known data of the urine flow reported by Kamemoto & Ono (Comp. Biochem. Physiol.27, 851–857, 1968), a probable function of anal water intake is discussed.

     

Lipoxygenase of the thermophilic bacteria thermoactinomyces vulgaris—properties and study on the active site

• 1.1. A lipoxygenase activity was purified from Thermoactinomyces vulgaris and some of its properties were characterized.
• 2.2. The enzyme showed a temperature activity range of 40–55°C with still significant activity over 60°C.
• 3.3. The pH of activity on linoleic acid had a broad range with an optimum at pH 6.0 and a weaker one at pH 11.0.
• 4.4. On arachidonic acid the pattern was narrow bell-shaped with an optimum at pH 6.5.
• 5.5. The purified lipoxygenase from Th. vulgaris showed an apparent K_m of 1 mM and V_max of 0.84 μmol diene/min/mg protein.
• 6.6. It was inhibited by the oxidation products, 9-HPOD and 13-HPOD.
• 7.7. A 160,000 Da molecular weight of the enzyme was determined by molecular filtration. Methionine, tyrosine, tryptophan and cysteine are apparently involved in its activity.

     

Effects of 2,4-dinitrophenol on trichomonads and Entamoeba invadens

• 1.1. 2,4-Dinitrophenol (2,4-DNP) in substrate level concentrations (200 μM-1 mM) temporarily inhibits H₂ production by Tritrichomonas foetus and Trichomonas vaginalis as well as the accumulation of metronidazole, dependent on its reduction by the two trichomonad species and by Entamoeba invadens.
• 2.2. 2,4-DNP competes for the reducing equivalents which are necessary for H₂ production or for the reduction of metronidazole, thereby inhibiting these processes. 2,4-DNP is reduced to 2-amino, 4-nitrophenol.
• 3.3. 2,4-DNP in concentrations up to 800 μM has no effect on the uptake of O₂ by these organisms.
• 4.4. 2,4-DNP has some toxicity for T. foetus.

     

Effects of temperature and acid stress on hatching,survival capacity,metabolism and postural reflexes in caenid mayflies (ephemeroptera)

• 1.1. Mortality was 100% at pH 3.5 over a temperature range of 10–30°C for embryos and nymphs of Caenis diminuta and C. hilaris.
• 2.2. Hatching success for both species was highest at pH values above 4.5.
• 3.3. Survival capacities were significantly higher at 20°C over a pH range of 4.0-7.2.
• 4.4. Oxygen consumption rates increase as a function of increasing temperature and reduced acidity.
• 5.5. Loss of the nymphal righting response was observed at pH 3.5. This response can be used as a behavioral assay for acid stress.

     

Chemical composition of North Atlantic krill

• 1.1. The main chemical components of Meganyctiphanes norvegica (M. Sars), Thysanoessa inermis (Krøyer) and T. raschii (M. Sars) have been examined.
• 2.2. Protein accounted for 42–47% of the dry weight of M. norvegica and 32–50% of the dry weight of the Thysanoessa species. On a wet weight basis, the protein content was relatively constant and independent of season.
• 3.3. The dominating amino acids in the bulk protein of the krill were glutamic acid/glutamine, aspartic acid/asparagine, glycine, alanine, lysine and leucine.
• 4.4. Lipids were present in amounts of 13–29% of the dry weight in M. norvegica, 15–50% in T. inermis and 12–44% in T. raschii, and the lipid content varied with season.
• 5.5. The main nitrogen extractives in krill, expressed on a dry weight basis, were free amino acids (5–10%), trimethylamine oxide (about 4%), peptides (about 1%) and nucleotides (0.4–1.3%). Trimethylamine and ammonia were present in very low concentrations in living krill.
• 6.6. The amino acids taurine, glycine, proline, arginine, sarcosine and alanine made up 89–93 mol% of the free amino acid pool.
• 7.7. The ash content of krill was in the order of 10–13% of the dry weight, and fluoride represented 1040 and 3200 ppm in the Thysanoessa species and M. norvegioca, respectively.

     

Temperature and salinity tolerance of the mole crab,Emerita talpoida (Say) (Crustacea,Anomura)

• 1.1. Adult Emerita talpoida were subjected to 25 temperature-salinity combinations within the range of 5–35°C and 15–65‰.
• 2.2. E. talpoida tolerated 15–65‰ salinity at 20°C and below.
• 3.3. Optimum salinity for survival at stressful temperatures was 40‰.
• 4.4. Crabs transferred directly from one salinity to another experienced changes in osmoconcentration toward that of the new salinity.
• 5.5. Temperature modified the rate of change toward the experimental salinity. Q values averaged 1.2.

     

Combined effect of adenosine,alpha adrenergic and adenosine antagonists on serum insulin and insulin secretion from rat pancreatic islets

• 1.1. The effect of adenosine separately or in combination with alpha-1 adrenergic antagonist prazosin and alpha-2 adrenergic antagonist yohimbine as well as adenosine antagonists 8-phenyltheophylline and xanthine amine conjugate on glucose-induced insulin secretion from isolated rat pancreatic islets was studied.
• 2.2. Their in vivo effects on serum glucose and insulin levels were also investigated. Adenosine at 10 and 100 μM inhibited significantly, insulin secretion from the isolated islets whereas at 10 mM slightly increased the secretion of insulin.
• 3.3. Prazosin used at 100 μM inhibited insulin secretion. When it combined with adenosine (10 μM) it augmented the inhibitory effect of adenosine.
• 4.4. In vivo prazosin (21 mg/kg bodywt) caused a hyperglycaemia which was accompanied by hypoinsulinaemia.
• 5.5. Concurrent administration of this drug with adenosine neither affect the hyperglycaemic nor the hypoinsulinaemic effects of adenosine.
• 6.6. On the other hand, yohimbine (100 μM) has no effect neither separately nor in combination with adenosine (10 μM) in modulating the inhibitory effect of adenosine on insulin secretion.
• 7.7. When Yohimbine administered at 19.5 mg/kg body wt it did not alter serum glucose but it markedly increased the serum insulin level. Its combined administration with adenosine reduced the hyperglycaemic effect of adenosine with a remarkable increase in serum insulin.
• 8.8. Both adenosine-antagonists were ineffective in alteration of insulin secretion.
• 9.9. However, combination of 8-phenyltheophylline with adenosine (10 μM) totally blocked the inhibitory effect of adenosine on insulin secretion while xanthine amine conjugate failed to prevent this effect of adenosine.
• 10.10. These results indicate that the inhibitory effect of adenosine on insulin secretion is neither mediated via alpha-1 nor alpha-2 adrenoceptors. It might be via activation of specific adenosine receptors on rat islets which are sensitive to blockade by 8-phenyltheophylline.

     

Ostrich fructose-1,6-bisphosphatase: Kinetic characterization of the liver isoenzyme

• 1.1. Purified ostrich (Struthio camelus) liver fructose-1,6-bisphosphatase exhibited an absolute requirement for Mg²⁺.
• 2.2. The enzyme catalyzed the hydrolysis of fructose-1,6-bisphosphate, sedoheptulose-l,7-bisphosphate and ribulose-l,5-bisphosphate.
• 3.3. S_0.5 for substrate was 1.4 μM.
• 4.4. AMP was a potent non-competitive inhibitor with respect to substrate (K_i of 25 μM).
• 5.5. Fructose-2,6-bisphosphate was a potent competitive inhibitor of the enzyme (K_i of 4.8 μM).

     

Effects of low environmental pH and temperature on hatching and metabolic rates in embryos of Anax junius drury (Odonata: Aeshnidae) and the role of hypoxia in the hatching process

• 1.1. Studies were conducted in order to determine the combined effects of low environmental pH and temperature on embryonic survival capacity and metabolic rates in the dragonfly, Anax junius Drury. Studies were also conducted to assess the effects of hypoxia on hatching success as well as to investigate the role of hypoxia as a possible physiological triggering mechanism for hatching.
• 2.2. At water temperatures of 10–30°C, an environmental pH value of 3.0 was extremely limiting and significantly reduced hatching success.
• 3.3. Over a pH range of 3.0–5.0, a water temperature of 30°C was found to be severely limiting. Over a pH range of 6.0–7.0, hatching success was greater than 80% at test temperatures ranging from 10 to 25°C.
• 4.4. Embryos of A. junius exhibited a greater tolerance to markedly low environmental pH (3.0) than that previously reported for fish and amphibians, although survival capacity was less than 10%.
• 5.5. An environmental pH value of 3.0 has a significant detrimental effect on embryonic development. Survivorship and developmental rate increase significantly over a pH range of 4.0–5.0.
• 6.6. Oxygen consumption rates were lowest for fertilized eggs exposed to a pH of 3.0 at all test temperatures (10–30°C). Metabolic rates increased significantly at pH 4.O.
• 7.7. Embryos hatch successfully under hypoxic conditions in both aqueous and nonaqueous media. Results suggest that hypoxia acts as a triggering mechanism for hatching in this aquatic insect.

     

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

• 1.1. The content of atrial natriuretic peptides (ANPs) in the auricles of oysters, Crassostrea virginica, was significantly (P < 0.01) greater than in their ventricles.
• 2.2. 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.
• 3.3. 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.
• 4.4. 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.
• 5.5. 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.

     

Absorption of glucose,glycine and palmitic acid by isolated midgut and hindgut from crickets

• 1.1. In vitro experiments indicated that midgut and hindgut anterior to the Malpighian tubules are important in absorption and processing of products of digestion in crickets.
• 2.2. Isolated hindguts from crickets (Gryllus assimilis, G. rubens and Scapteriscus acletus) absorbed and released into the incubation medium 20–30% of a load of [¹⁴C]glucose and 29–31% of a load of[¹⁴C]glycine.
• 3.3. Isolated midguts from the same crickets absorbed and released into the incubation medium 30–50% of the glucose and 43–52% of the glycine load.
• 4.4. Radiolabelled palmitate was absorbed into epithelial cells of isolated mid- and hindguts, but little was transported and released into the incubation medium.