Prostaglandin E1 and analogs of prostacyclin influencing superoxide production by the human neutrophil nadph oxidase system

• 1.1. The effects of prostaglandin (PG) E₁, and I₂ analogs (OP-41483 and OP-2507) on the Superoxide generation of human neutrophil NADPH oxidase (EC 1.6.99.6) in both whole-cell and cell-free systems were investigated.
• 2.2. In a whole-cell system, OP-2507 inhibited the Superoxide generation by neutrophils exposed to phorbol myristate acetate concentration-dependently through its superoxide-scavenging action.
• 3.3. The concentration of the drug required for 50% inhibition of the oxidase (IC₅₀) was 21 μM.
• 4.4. In a cell-free system, however, the drug in concentrations of < 100 μM did not inhibit the activation of NADPH oxidase by sodium dodecyl sulfate because of its inactivation by the detergent.
• 5.5. Although PGE₁ and OP-41483 did not inhibit the Superoxide production by stimulated neutrophils in a whole-cell system, they both inhibited the activation of NADPH oxidase in a cell-free system concentration-dependently, with IC₅₀ values of 44 and 170 μM, respectively.
• 6.6. In addition, in the cell-free system, the K_m value for NADPH of the oxidase was unchanged by PGE₁.
• 7.7. The results suggest that the PGI₂ analog, OP-2507, is a possible superoxide-scavenger and that PGE₁ inhibits the NADPH oxidase activation by sodium dodecyl sulfate in a cell-free system concentration-dependently.

     

Effects of a purine inhibitor,allopurinol, on urate metabolism in the german cockroach,Blattella germanica L. (Dictyoptera: Blattellidae)

• 1.1. Adult male and female cockroaches (Blattella germanica) were maintained on a positive nitrogen balance diet (66% protein) containing various levels of allopurinol (0–3%) to determine the effects of allopurinol on urate synthesis and storage.
• 2.2. Each insect was injected with [¹⁴C]hypoxanthine and after 1 week was analyzed for whole-body hypoxanthine, xanthine and urate radiolabel.
• 3.3. There was a general trend of decreased whole-body radiolabel retention, radiolabeled body urates and total-body urate content in both sexes with increasing amounts of dietary allopurinol.
• 4.4. Virgin female adults were allowed to feed on diets containing 0, 25 and 66% protein plus 0.1% allopurinol and were injected with [¹⁴C]xanthine.
• 5.5. After 1 week radiolabel content in the whole-body xanthine and urate pools was determined.
• 6.6. Females on the 0% protein diets contained less radiolabel in the whole-body and body urates than those on either 25 or 66% protein diets.

     

Effect of methyl methacrylate on mitochondrial function and structure

• 1.1. Treatment of isolated rat liver mitochondria with methyl methacrylate (MM) produced membrane disruption as evidenced by the release of citrate synthase, and changes in the ultrastructure of mitochondria.
• 2.2. At concentration 0.1%, MM uncoupled oxidative phosphorylation as evidenced by stimulation of state 4 respiration supported either by pyruvate plus malate or succinate (+rotenone) and ATP-ase activity in intact mitochondria.
• 3.3. At concentration 1% MM stimulated ATP-ase activity in intact mitochondria and succinate (+rotenone) oxidation at state 4 and was without effect on this substrate oxidation at state 3.
• 4.4. MM inhibited pyruvate plus malate oxidation either at state 3 or in the presence of uncoupling agents.
• 5.5. MM inhibited the NADH oxidase of electron transport particles at a concentration which failed to inhibit either succinic oxidase or the NADH-ferricyanide reductase activity.
• 6.6. The data presented suggest that in the isolated mitochondria MM inhibits NADH oxidation in the vicinity of the rotenone sensitive site of complex I.
• 7.7. The general conclusion is that MM may block an electron transport and to uncouple oxidative phosphorylation in rat liver mitochondria. The overall in vitro effect would be to prevent ATP synthesis which could result in cell death under in vivo conditions.

     

Bioconcentration of chlorinated anilines and benzene in fish: Preliminary results

• 1.1. Seven chlorinated anilines and one chlorinated benzene were tested for their ability to bioconcentrate in guppies (Poecilia reticulata) under different experimental conditions.
• 2.2. Interactions between compounds in a mixture influence the bioconcentration of some chlorinated anilines. These interactions result in either an increase or a decrease of bioconcentration, depending on the compound studied.
• 3.3. Exposure concentration can have an effect on the extent of bioconcentration of some chlorinated anilines.

     

Gender-related differences of mouse liver d-aspartate oxidase in the activity and response to administration of d-aspartate and peroxisome proliferators

• 1.1. The hepatic d-aspartate oxidase activity was found to be higher in female ddY and ICR mice than in their male counterparts. On the contrary, the free d-aspartate content in the liver was lower in female mice than in male mice, suggesting that d-aspartate is actually metabolized by d-aspartate oxidase in vivo.
• 2.2. Oral administration of d-aspartate to the animals increased the hepatic d-aspartate oxidase activity 2–3 fold in both genders without any significant difference in the rate of the increase between the genders.
• 3.3. Several peroxisomal enzyme activities other than d-aspartate oxidase examined were not affected by this treatment.
• 4.4. Experiments in vitro suggested that the increase in the d-aspartate activity might be explained in part by stabilization of the enzyme by d-aspartate.
• 5.5. The administration of clofibrate, a peroxisome proliferator, to male mice, increased the hepatic d-aspartate oxidase activity with a significant simultaneous decrease of d-aspartate content in the liver, in agreement with a possible role of the enzyme n vivo.
• 6.6. On the other hand, the administration of clofibrate or dehydroepiandrosterone to female mice decreased the d-aspartate oxidase activity.
• 7.7. The peroxisome proliferators were suggested to act to eliminate the gender difference of hepatic d-aspartate oxidase activity in mice.

     

Occurrence of d-alanine in the eggs and the developing embryo of the sea urchin Paracentrotus lividus

• 1.1. d-Alanine has been found in appreciable amounts in the eggs and embryos of the sea urchin Paracentrotus lividus.
• 2.2. The content of d-alanine, expressed as pmol/egg or embryo, is 1.32 in the egg, 0.81 in the blastula, 0.54 in the gastrula and 0.60 in the pluteus.
• 3.3. The percentage of d-alanine with respect to the total alanine (d + l) decreases during embryonic development.
• 4.4. d-Amino acid oxidase, d-alanine transaminase and d-alanine racemase activities were found neither in eggs nor in embryos.
• 5.5. Therefore, it does not appear likely that d-alanine is subject to oxidative metabolism.
• 6.6. The decrease in this d-amino acid during development may be due to its utilization in the synthesis of a more complex molecule.

     

Purification and properties of glycollate oxidase from Lemna minor L.

• 1.1. Glycollate oxidase has been purified to apparent homogeneity from Lemna minor L. grown on medium containing 7mM NO⁻₃.
• 2.2. The enzyme is a highly basic protein with a sub-unit molecular weight of 42,000 and a holoprotein molecular weight of 250,000.
• 3.3. The Lemna enzyme is a flavoprotein with a broad specificity for straight chain α-hydroxy acids, the preferred substrate being glycollate.
• 4.4. It is also competitively inhibited by oxalate and phenyllactate.
• 5.5. A comparison is drawn between the physical properties of glycollate oxidase from a number of higher plants and the degree of sub-unit aggregation in the resulting protomers.

     

Human seminal phosphatase: Properties and comparison with plant phosphatases

• 1.1. Phosphatase activities were determined in various seminal fluid and plant tissues.
• 2.2. Human semen showed a markedly higher phosphatase activity, and some plants and mushrooms exhibited a considerably higher phosphatase activity.
• 3.3. Phosphatase purified from human seminal fluid showed a pH optimum of 5–6 and was potently inhibited by l-(+)-tartrate.
• 4.4. Tartrate could not inhibit most plant phosphatases, but inhibited the mushroom phosphatase with a one-order lower affinity than that of the seminal enzyme.

     

Ribosome inactivating protein-like activity in seeds of diverse Cucurbitaceae plants

• 1.1. Seed extracts of 20 plants species belonging to the family Cucurbitaceae were examined for their ability to inhibit protein synthesis in rabbit reticulocyte lysate and induce mid-term abortion in mice.
• 2.2. Eleven extracts were found to inhibit protein synthesis by about or over 90%, seven extracts produced about 80% inhibition, one caused about 70% inhibition and one brought about approx. 40% inhibition, when the extracts were tested at a final concentration of 10 μg per ml.
• 3.3. All of the seed extracts possessed potent mid-term abortifacient activity.
• 4.4. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the seed extracts disclosed the existence of a Coomassie Blue-stainable band with a mol. wt of ca 30,000 Da. This band probably accounts for the protein synthesis inhibiting and mid-term abortifacient activities.
• 5.5. There was a similarity in the electrophoretograms of seed extracts of plants belonging to the same genus.

     

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.

     

Cloning and characterization of rabbit pancreatic colipase

• 1.1. Among the digestive enzymes synthesized by pancreas, lipase is the principle lipolytic enzyme which hydrolyses dietary glycerides.
• 2.2. For its action it requires a coenzyme, colipase.
• 3.3. The molecular mechanisms of the interaction of these two are not fully understood.
• 4.4. Further, molecular events that regulate and influence lipid absorption are ill denned.
• 5.5. The rabbit is the conventional animal model for the study of lipid absorption. We have undertaken the molecular cloning, and characterization of rabbit pancreatic colipase, the coenzyme for pancreatic lipase.
• 6.6. Colipase has been cloned from a gt 11 library of an adult rabbit pancreatic cDNA by probing with an oligonucleotide derived from human colipase sequence.
• 7.7. The total reading frame consists of 321 nucleotides coding for 90 amino acids of the functional protein and 17 nucleotides of the leader peptide.
• 8.8. Northern blot analysis revealed a distinct band around 0.5kb. Comparison with other species revealed an over all homology of 75% at the nucleotide level.
• 9.9. At the amino acid level highest conservation is observed at the lipase-binding region (AA 53–73).
• 10.10. Rabbit enzyme also retained the N-terminal pentapeptide of it preform.
• 11.11. The regions of homology and conservation may aid to define the sites of interaction of colipase with lipase.

     

Investigation of ribosome inactivating protein-like activity in tissues of cucurbitaceae plants

• 1.1. Extracts of roots, seeds and fruits of seventeen plant species belonging to Family Cucurbitaceae were examined for the ability to inhibit protein synthesis in rabbit reticulocyte lysate and induce mid-term abortion in mice.
• 2.2. Out of the 22 tissue extracts examined, 16 were found to inhibit protein synthesis by >90%, three caused 65–85% inhibition and 3 caused <25% inhibition.
• 3.3. In general, there was a close correlation between protein synthesis inhibiting activity and mid-term abortifacient activity of the tissue extracts.
• 4.4. SDS-PAGE of the tissue extracts revealed the presence of a Coomassie Blue-stainable band with a mol. wt of ca 30,000. The data suggest that this band is responsible for the protein synthesis inhibiting and mid-term abortifacient activities.

     

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On the synthesis and incorporation of catalase and urate oxidase into the peroxisomes of mouse liver

• 1.1. The processes associated with the biogenesis of peroxisomes in mouse liver have been studied by following the incorporation of radiolabelled leucine into major enzymic components of this organelle.
• 2.2. Maximal incorporation of label into peroxisomal catalase and urate oxidase occurred within 2 hr, with the urate oxidase being labelled before catalase, but subsequent to the incorporation of phospholipid into this organelle.
• 3.3. Subsequently, immunoprecipitation of catalase from the large granular fraction of mouse liver was shown to result in the isolation of a catalase molecule which had lost a peptide of approx. 2000 dalton from each subunit by comparison with the newly-synthesized enzyme.
• 4.4. It was observed that the modification of catalase was obviated by the presence of leupeptin and iodoacetamide and this information has enabled the purification of both modified and unmodified forms of the enzyme.
• 5.5. The possible significance of these data has been discussed and the major features incorporated into a working model of peroxisomal biogenesis.

     

Disruption of endothelial barrier function: relationship to fluidity of membrane extracellular lamella

• 1.1. Endothelial cells were cultured in tissue culture flasks or on microcarrier beads and labeled with a lipid specific spin-label.
• 2.2. Exposure of endothelial cells to benzyl alcohol caused a dose- and time-dependent increase in membrane fluidity using electron spin resonance (ESR). Maximum fluidity was reached after a 5-min exposure to 100 mM benzyl alcohol.
• 3.3. Albumin permeability across endothelial cells cultured on micropore filters was used as an indication of endothelial monolayer integrity.
• 4.4. A significant increase in permeability occurred with 50 mM benzyl alcohol. Maximal albumin permeability was reached after a 5-min exposure to 100 mM benzyl alcohol.

     

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The formation of a dimeric product of raffinose by the action of galactose oxidase

• 1.1. Galactose oxidase is known to catalyze the oxidation of the C-6 hydroxymethyl group of galactose to an aldehyde group.
• 2.2. When the products of a galactose oxidase-catalase treatment of raffinose were examined by gel filtration and ion exchange chromatography, we found that in addition to the expected 6'-aldehydoraffinose, two other components were present.
• 3.3. One component was neutral and had an elution volume close to that of maltopentaose and on treatment with sodium borohydride or hypoiodite, this component was converted to raffinose or 6'-carboxyraffinose, respectively.
• 4.4. Fast atom bombardment mass spectroscopy in the negative mode indicated that the major molecular ion had an M/Z of 1003.
• 5.5. These data are consistent with this component being a dimer of 6'-aldehydoraffmose.

     

2-Deoxyglucose transport by the frog sartorius: Effects of electrical stimulation and N-carbobenzoxy-glycyl-l-phenylalaninamide

• 1.1. Studies characterizing glucose transport in the frog sartorius were performed.
• 2.2. For nonstimulated and stimulated muscles, intracellular 2-deoxyglucose exceeded 2-deoxyglucose-6-phosphate at 15 min, showed little further increase, and was maintained below the extracellular concentration for 2 hr.
• 3.3. Accumulated 2-deoxyglucose-6-phosphate did not inhibit glucose transport.
• 4.4. Unlike in adipocytes, basal and stimulated 2-deoxyglucose transport showed no difference in sensitivity to N-carbobenzoxy-glycyl-l-phenylalaninamide.
• 5.5. Phenylarsine oxide blocked contraction-enhanced 2-deoxyglucose uptake.
• 6.6. These results suggest that the glucose transporter of the sartorius exhibits auto-regulation, and that basal transport is not regulated by the same process as in adipocytes.

     

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Breast,hips, and buttocks revisited: Honest fatness for honest fitness

This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:

• 1.1. Sexual selection has probably not been the most important selection pressure on
• 2.female human body shape.
• 3.2. Male humans in different cultures find different aspects of the female body attractive
• 4.and therefore are unlikely to have exerted consistent directional sexual selection on
• 5.the female body.
• 6.3. Breast size is not correlated with lactation success.
• 7.4. Visible hip width is not correlated with parturition success.
• 8.5. Women would lower their fitness if they tried to deceive men about their internal
• 9.pelvic dimensions.
• 10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
• 11.breast, hips, and buttocks.