Influence of β-alanine on ultrastructure,tanning, and melanization of Drosophila melanogaster cuticles

In Drosophila melanogaster, the chitinous microfibrils arising from the tips of the epidermal villi in adult cuticles remain irregular and loose in the mutant ebony (which fails in cuticular incorporation of -alanine) but closely knit and regular in normal flies. Addition of -alanine to cuticles from which nonchitinous materials have been removed with alkali converts the loose arrangement of the microfibrils to a compact and sharply delineated arrangement. -alanine also accelerates tyrosinase-catalyzed oxidation of N-acetyldopamine by reacting with the oxidized product of the reaction to produce an orange-red complex. Similarly, -alanine accelerates oxidation of N-acetyldopamine when these two substances are added to fluids from the hemocoel, to lead to tanning instead of normal blackening. These findings may help explain why -alanine induces tanning while inhibiting melanization in insects.This study was supported by Grant GM-18680 from the National Institutes of Health.     

Effect of weight and storage time of broiler breeders’ eggs on morphology and biochemical features of eggs,embryogenesis, hatchability,and chick quality

The transfer of hatchability results obtained under experimental conditions to the commercial ground with a positive financial effect proves the value and usefulness of these data. On the other hand, finding results on commercial processes of broiler breeders’ egg incubation in the literature is challenging. The presented study aimed to determine the effects of egg weight and storage time on the physical, biochemical characteristics of hatching eggs, embryogenesis and hatchability in Ross 308 broiler breeders. On the laying day, the eggs were divided into four weight groups: S – small eggs (57–61 g), M – medium eggs (62–66 g), L – large eggs (67–71 g), and XL – extra-large eggs (72–76 g). The eggs were then stored for 3, 7, 14, and 21 days under controlled conditions. As the egg storage time increased, a decrease in the yolk quality (lower index) was observed. The highest Haugh units were found in eggs from the S and M groups. The cholesterol content of the M, L, and XL groups was lower on days 7, 14, and 21 as compared to that of eggs only stored for 3 days. Egg weight loss during incubation decreased with an increase in the egg weight. An extension of the egg storage time caused an increase in the loss of egg weight. On the 14th and 18th days of hatching, an increase in the eggshell temperature was noted with an increase in the weight of the egg. The eggs stored for 7 days were characterised by the highest shell temperature on each day. The highest hatchability percentage was recorded for the M group. The hatchability rate decreased with the prolongation of the storage time, while the number of crippled chicks after hatching increased. The results confirmed that the increased weight of the eggs and prolonged storage time (14 and 21 days) increased the weight and decreased the length of the newly hatched chicks, respectively. Chicks from the heaviest eggs and those stored for 14 and 21 days showed poor results on the Pasgar score® test. The observations indicate the need to adopt various (of those available) methods to assess the quality of newly hatched chicks in hatcheries in order to produce high-quality broiler chickens. The results also indicate that prolonged egg storing beyond 14 days may affect the thyroid hormone economy during the hatching of chicks, especially in the XL group.     

Effects of creatine and its analog, β-guanidinopropionic acid, on the differentiation of and nucleoli in myoblasts

The effects of supplementation with creatine (Cr) and its analog, β-guanidinopropionic acid (β-GPA), on the differentiation of myoblasts and the numbers of nucleoli were studied in C2C12 cells. The cells were cultured in differentiation medium for 4 d. Then Cr (1 mM) or β-GPA (1 mM) was added to the cells, and the mixture was cultured for an additional 2 d. Although the number of myotubes was not different among the groups, myotube diameters and nuclear numbers in myotubes were increased by Cr and β-GPA treatment respectively. The expression of differentiation marker proteins, myogenin, and the myosine heavy chain, was increased in the β-GPA group. Supplementation with β-GPA also increased the percentage of p21 (inhibitor for cell cycle progression)-positive myoblasts. Supplementation with Cr inhibited the decrease in nucleoli numbers, whereas β-GPA increased nucleolar sizes in the myotubes. These results suggest that β-GPA supplementation stimulated the differentiation of myoblasts into multi-nucleated myotubes through induction of p21 expression.     

Biological activities of the LXRα and β agonist, 4β-hydroxycholesterol,and of its isomer, 4α-hydroxycholesterol,on oligodendrocytes: Effects on cell growth and viability,oxidative and inflammatory status

The biochemical and biological properties of 4β-hydroxycholesterol and of its isomer, 4α-hydroxycholesterol, are not well known. So, we determined the ability of 4α- and 4β-hydroxycholesterol to react with LXRα and LXRβ, and we characterized the activities of these oxysterols on oligodendrocytes which are myelin synthesizing cells. The effects of 4α- and 4β-hydroxycholesterol were studied on 158N murine oligodendrocytes to assess their activities on cell growth and viability, oxidative and inflammatory status. To this end different parameters were used: cell counting with trypan blue; identification of dead cells and cell cycle analysis with propidium iodide; evaluation of mitochondrial depolarization, lysosomal membrane integrity, actin depolimerization, nuclear morphology, and superoxide anion production after staining with JC-1, acridine orange, rhodamine-phalloidin, Hoechst 33342, and dihydroethidium, respectively; evaluation of ultrastructural changes by transmission electron microscopy, and cytokine quantification with a cytometric bead array. Only 4β-hydroxycholesterol is a LXRα and β agonist. No cytotoxic effects were found with 4α-hydroxycholesterol except a slight inhibition of cell growth at elevated concentrations. At high concentrations, 4β-hydroxycholesterol was not only able to inhibit cell growth, but also to induce cell death associated with a loss of mitochondrial transmembrane potential, dysfunctions of lysosomal membrane integrity, and superoxide anion overproduction. These side effects were lower than those observed with 7-ketocholesterol and 25-hydroxycholesterol used as positive controls. On oligodendrocyte murine primary cultures, only lysosomal membrane integrity was slightly affected under treatment with 4α- and 4β-hydroxycholesterol. So, 4α- and 4β-hydroxycholesterol have different biological activities. Their ability to induce cytotoxic effects on oligodendrocytes can be considered as weak comparatively to 7-ketocholesterol and 25-hydroxycholesterol.     

Effects of Eution Conditions on the Separation of Calpastatin, μ- and m-Calpain on DEAE-Sephacel Chromatography

A rapid stepwise measurement for the activities of calpastatin and μ- and m-calpains was developed by using 2-stage elution at pH 8.5 and then 7.0. The activities of calpastatin, μ-calpain and m-calpain can be rapidly assayed following the separation on DEAE-Sephacel chromatography by a 2 stage elution with 90 mM NaCl (pH 8.5), and then by 200 and 300 mM NaCl in elution buffer (pH 7.0). No significant differences in the recovery of these proteinases and inhibitor was observed between stepwise gradient and linear gradient methods.     

Effect of uniconazole and limited water on growth,water relations,and mineral nutrition of “Lalandei” Pyracantha

Pyracantha (Pyracantha coccinea M. J. Roem. Lalandei) plants were treated with uniconazole at 0.5 mg ai container^–1 as a medium drench, 150 mg ai L^–1 as a foliar spray, or left untreated. Plants from all treatments were placed under three water regimes: drought acclimated, nonacclimated and later exposed to drought, or nonstressed. Acclimated plants were conditioned by seven 4-day stress cycles (water withheld), while nonacclimated were well watered prior to a single 4-day stress cycle at the same time as the seventh drought cycle of acclimated plants. Nonstressed plants were well watered throughout the study. Nonstressed plants had higher leaf water potentials and leaf conductances than acclimated and nonacclimated plants, and transpiration rates were higher in nonacclimated than acclimated plants. Uniconazole did not affect leaf water potential, leaf conductance, or transpiration rate. Acclimated plants had smaller leaf areas and leaf, stem, and root dry weights than nonacclimated or nonstressed plants. Plants drenched with uniconazole had the lowest stem and root dry weights. Acclimated plants also contained higher N concentrations than nonacclimated or nonstressed plants, and higher P concentrations than nonacclimated plants. Uniconazole medium drench treatments increased levels of Mn and P. Calcium concentration was increased in plants receiving either medium drench or foliar applications.     

Differential effects of d-amphetamine, β-phenylethylamine,cocaine and methylphenidate on the rate of dopamine synthesis in terminals of nigrostriatal and mesolimbic neurons and on the efflux of dopamine metabolites into cerebroventricular perfusates of rats

The $\text{in}$$\text{vivo}$ of four psychomotor stimulants (d-amphetamine, β-phenylethylamine, cocaine and methylphenidate) were determined on: 1) the rate of dopamine (DA) synthesis, as measured by the accumulation of dihydroxyphenylalanine (DOPA) after aromatic L-amino acid decarboxylase inhibition, in the striatum (terminals of nigrostriatal neurons) and in the nucleus accumbens and olfactory tubercle (terminals of mesolimbic neurons) and 2) the efflux of the DA metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) into cerebroventricular perfusates of conscious, freely-moving rats. d-Amphetamine and β-phenylethylamine produced biphasic responses with lower doses of each drug increasing both the efflux of DOPAC and the rate of DA synthesis in the striatum. Higher doses of each drug either had no effect or actually decreased the efflux of DOPAC and also decreased the rate of DA synthesis in the striatum. Higher doses of each drug either had no effect only decreased the efflux of DOPAC and the rate of DA synthesis in the striatum. The effects of the drugs on the rate of DA synthesis in the nucleus accumbens and olfactory tubercle were similar to, but less pronounced than those seen in the striatum. These results are consistent with the following suggestions: 1) low doses of d-amphetamine and β-phenylethylamine facilitate the neuronal release of DA while higher doses of both drugs facilitate release and inhibit neuronal reuptake of the amine, and 2) cocaine and methylphenidate preferentially block the neuronal reuptake of DA.     

Effect of estradiol-17 β on the cytology of the liver,gonads and pituitary,and on plasma electrolytes in the female freshwater eel

Summary Female freshwater eels injected with estradiol-17 (E2) for 15–78 days appear paler and secrete more mucus than controls. The resulting strongly opalescent blood plasma indicates that vitellogenin synthesis occurs in the liver, which shows a significant hypertrophy, an increased vacuolization (lipid material) and glycogen depletion. Plasma sodium is lowered, but calcium levels are considerably increased. The gonosomatic index increases (0.92±0.1 to a maximum of 2.21). Oocytes are enlarged, but the incorporation of vitellogenin remains discrete. Gonadotrophs (GTH cells), small and scarcely visible in the pituitary of control eels, are hypertrophied and contain numerous glycoprotein granules after E2-administration. E2 may act on the pituitary and/or hypothalamus via a positive feedback to induce gonadotrophin (GTH) synthesis; GTH release seems to be very limited as indicated by the ovarian response. The differentiation of GTH cells in eels treated with fish pituitary extracts is most probably due to secretion of E2 by the ovary, which reacts on the pituitary. Various hypotheses are considered to explain the low GTH release.Thyrotrophs, somatotrophs and prolactin cells of the pituitary are stimulated. In the pars intermedia, MSH and PAS-positive cells appear less active. A possible antidopaminergic effect of E2 is discussed.E2 administration constitutes a simple and economic technique to induce the synthesis of GTH and will facilitate the biochemical and biological study of the latter hormone in eels.     

Kinetic and thermodynamic analysis of the inhibitory effects of maltose,glucose, and related carbohydrates on wheat β-amylase

Inhibition of wheat β-amylase (WBA) by glucose and maltose was studied by kinetics and thermodynamics. The inhibitory effects of fructose, difructose, sucrose, trehalose, cellobiose, acarbose, and 1-deoxynojirimycin on WBA were also evaluated. The half maximal inhibitory concentrations (IC₅₀) of acarbose, maltose and glucose were 0.06 ± 0.01 M, 0.22 ± 0.09 M, and 1.41 ± 0.17 M, respectively. The inhibitor constant (K_i) and the thermodynamic parameters such as changes in Gibbs energy (ΔG), enthalpy (ΔH), and entropy (ΔS) of the dissociation reactions of the WBA-glucose and WBA-maltose complexes were temperature and pH-dependent. The dissociation reactions were endothermic and enthalpy-driven. Both glucose and maltose behaved as competitive inhibitors at pH 3.0 and 5.4 at a temperature of 25 °C with respective K_i values of 0.33 ± 0.02 M and 0.12 ± 0.03 M. In contrast, both sugars exhibited uncompetitive inhibition at pH 9 at a temperature of 25 °C with K_i values of 0.21 ± 0.03 M for glucose and 0.11 ± 0.04 M for maltose. The pH-dependence of the inhibition type and K_i values indicate that the ionizing groups of WBA influence drastically the interaction with these carbohydrates. This evidence enables us to consider temperature and pH in the WBA-catalyzed hydrolysis to manipulate the inhibition by end-product, maltose, and even by glucose.     

Effects of 50 Hz electromagnetic fields on the histology,apoptosis, and expression of c-Fos and β-Catenin on the livers of preincubated white leghorn chicken embryos

Reports have demonstrated occurrences of abnormalities in the early stages of chicken embryonic development due to the exposure to electromagnetic fields (EMFs). This article was designed to investigate the effects of sinusoidal EMF on the histopathology, apoptosis, and expressions of c-Fos and β-Catenin genes of the livers of preincubated White Leghorn chicken embryos, based on our published experiments. 300 healthy, fresh fertilized eggs were divided into control (n = 70), sham (n = 70), and four experimental (1–4,days 13, 14, 5, and 19, n = 40) groups. Experimental eggs were exposed to the most effective intensity in a coil with 7.32 mT density, and sham groups were also located in the same coil with no exposure, both for 24 h before incubation. Control, sham, and experimental groups were then incubated in an incubator (37°C, humidity 60%) for 13,14,15, and 19 days. Livers of 13–15 and 19 day-old chicken embryos were removed by C-section and fixed in formalin (10%), stained with Hematoxylin-Eosin and TUNEL for histopathological and apoptosis studies. Others were used for investigating c-Fos and β-Catenin expressions, using RT-PCR. Results showed extensive hemorrhages all over the chicken embryos' bodies and livers, more lymphoid tissues, disturbed parenchymal tissues, sinusoid denaturation, vesiculizad cytoplasm, an increase in the number of apoptotic cells, and a decrease on the levels of expressions of c-Fos and β-Catenin genes in experimental groups of 1–4, comparing control and sham groups.     

Effects of 50 Hz electromagnetic fields on the histology, apoptosis, and expression of c-Fos and β-catenin on the livers of preincubated white Leghorn chicken embryos

Reports have demonstrated occurrences of abnormalities in the early stages of chicken embryonic development due to the exposure to electromagnetic fields (EMFs). This article was designed to investigate the effects of sinusoidal EMF on the histopathology, apoptosis, and expressions of c-Fos and β-Catenin genes of the livers of preincubated White Leghorn chicken embryos, based on our published experiments. 300 healthy, fresh fertilized eggs were divided into control (n?=?70), sham (n?=?70), and four experimental (1-4,days 13, 14, 5, and 19, n?=?40) groups. Experimental eggs were exposed to the most effective intensity in a coil with 7.32?mT density, and sham groups were also located in the same coil with no exposure, both for 24?h before incubation. Control, sham, and experimental groups were then incubated in an incubator (37°C, humidity 60%) for 13,14,15, and 19 days. Livers of 13-15 and 19 day-old chicken embryos were removed by C-section and fixed in formalin (10%), stained with Hematoxylin-Eosin and TUNEL for histopathological and apoptosis studies. Others were used for investigating c-Fos and β-Catenin expressions, using RT-PCR. Results showed extensive hemorrhages all over the chicken embryos' bodies and livers, more lymphoid tissues, disturbed parenchymal tissues, sinusoid denaturation, vesiculizad cytoplasm, an increase in the number of apoptotic cells, and a decrease on the levels of expressions of c-Fos and β-Catenin genes in experimental groups of 1-4, comparing control and sham groups.     

Effects of local and repeated systemic administration of (−)nicotine on extracellular levels of acetylcholine,norepinephrine, dopamine,and serotonin in rat cortex

Systemically administered (–)nicotine (0.2–1.2 mg/kg, s.c.) significantly increased the release of acetylcholine (ACh), norepinephrine (NE) and dopamine (DA) in rat cortex. The lowest dose of (–)nicotine examined (0.2 mg/kg, s.c) also significantly elevated extracellular serotonin (5-HT) levels, and the maximal increases of extracellular ACh (122% at 90 min post injection) and DA levels (249% at 120 min post-injection) were observed following this dose. In contrast, the maximal increase of NE release (157% at 30 min post-injection) was observed following the highest dose of (–)nicotine injected (1.2 mg/kg, s.c.). This higher dose consistently produced generalized seizures. Repeating the (–)nicotine (0.58 mg/kg, s.c.) injection four hours after the first administration significantly elevated extracellular NE levels and also appeared to increase DA and CCh release. In addition, extracellular ACh and DA levels increased significantly in the dialysate after (–)nicotine was administered directly to the neocortex through the microdialysis probe membrane. Norepinephrine levels appeared to be elevated in the cortex following local administration as well.     

Effects of age on fresh weight,proteins, peroxidases,and other enzymes of the +, −, and crossed gymnothecial cultures of Nannizzia gypsea

Cultures of the + (UAMH 1485) and — (UAMH 1486) mating types of Nannizzia gypsea and their crosses (1485×1486) were analyzed, after 1, 2, 3, and 4 weeks growth, for fresh weight, proteins, peroxidases, esterases, acid- and alkaline-phosphatases. The + type produced slightly more growth at all periods (90, 131, 131, and 129 mg/plate) than the — mating type (90, 123, 121, and 108 mg/plate). The growth of the crosses was much less (30, 88, 83, and 94 mg/plate). Total soluble proteins per gram fresh weight was greater for the crosses (51, 33, 48, and 63 mg) than for the + (19, 32, 34, and 32 mg) and — (20, 33, 33, and 33 mg) strains. Disc-gel electrophoretic analyses revealed 6–9 protein bands in each of the mating types, and 7–8 bands (protein) in crosses, several of which showed mobility and stain uptake differences. There were 1–2 peroxidase bands in the +, -, and crosses; their patterns were generally the same in 1-week-old cultures, but slight differences were found at the subsequent harvests. The number of esterases in the +, -, and crosses was 3–4 and 2–3, respectively, but their patterns were similar. Acid- and alkaline-phosphatases of the + and -, and crosses were quite similar to one another. For all the enzymes studied, the number of bands increased after the first harvest in crosses, but in the single strains there was no constant pattern.

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Zusammenfassung Kulturen von + (UAMH 1485) und — (UAMH 1486) Zuchtungstamme von N. gypsea und ihre Kreuzungen (1485×1486) waren analisiert (nach 1-, 2-, 3- und 4-Wochen-wachsen) fur frisches Gewicht, Proteinnen, Peroxidasen, Esterasen, seurige und alkalinische Phosphatasen. Die + Stamme zeigten immer etwas besseres Entwicklung (123, 131, 131, und 129 mg/Platte) Denn die – (90, 123, 121, und 80 mg/Platte).Die Kreuzungen zeigten immer viel weniger Wachstum (30, 88, 83, und 94 mg/Platte). Die total losbare Protein per gram von frischen Gewicht war immer grosser bei den kreuzungen (51, 33, 48, und 63 mg) denn fur die + (19, 32, 34, und 32 mg) und die – (20, 33, 33, und 33 mg) Stamme.Die Disk-gel Electrophoretic Analysis zeigte 6–9 Protein Bande in allen Zuchtungstammen und 7–8 Bande in den Kreuzungen, mehrere zeigten verschiedene Beweglichkeiten und die Einahme der Beize. Wir sahen 1–2 peroxidase Bande in die +, –, und in den kreuzungen; ihre Formen (Muster) waren fast immer gleich wie in der ersten Woche alte Kulturen, aber etwas verschiedenes konnte man doch sehen spater in den ernten.Die Nummer von die Esterasen in die + und – Stamme und in die kreuzungen war 3–4 und 2–3, beziehungsweise aber die die Mustern waren gleich. Die surige und lauge Phosphatasen von den +, –, und von den Kreuzungen waren ziemlich gleich.In alle Enzyme die wir untersucht haben, die Nummer von den Bandern ist immer hoher geworden nach die erste Ernte in den Kreuzungen, aber in den einzelnen Stammen es war standiges Muster.

     

Effect of prolyl-leucyl-glycinamide and α-melanocyte-stimulating hormone on levorphanol-induced analgesia,tolerance and dependence

Prolyl-leucyl-glycinamide (PLG) at a low dose (10 ng/mouse) administered by an intracerebroventricular (i.c.v.) injection did not affect levorphanol analgesia, but PLG at higher doses (10 and 100 μg/mouse) and α-melanocyte-stimulating hormone (α-MSH) (10 ng/ mouse) antagonized levorphanol analgesia. Development of levorphanol tolerance was facilitated by 10 ng/mouse of PLG, unaffected by 10 μg/mouse of PLG, but antagonized by 100 μg/mouse of PLG and 10 ng/mouse of α-MSH. The effect of PLG on levorphanol dependence was assessed by changes in body weight and temperature during naloxone-induced withdrawal. PLG (10 ng/mouse) facilitated the development of levorphanol dependence, but 10 μg/mouse of PLG had no effect. PLG (100 μg/mouse) antagonized development of levorphanol dependence. PLG at doses of 10 and 100 μg/mouse precipitated withdrawal in levorphanol-dependent mice. α-MSH (10 ng/mouse) antagonized development of levorphanol dependence as evidenced by an increase in the ED50 of naloxone required to induce withdrawal jumping. These results indicate that PLG and α-MSH affected levorphanol-induced analgesia, tolerance and dependence in a qualitatively similar manner to their effect on morphine-induced analgesia, tolerance and dependence.     

Adsorption of glycinin and β-conglycinin on silica and cellulose: surface interactions as a function of denaturation, pH, and electrolytes

Soybean proteins have found uses in different nonfood applications due to their interesting properties. We report on the kinetics and extent of adsorption on silica and cellulose surfaces of glycinin and β-conglycinin, the main proteins present in soy. Quartz crystal microgravimetry (QCM) experiments indicate that soy protein adsorption is strongly affected by changes in the physicochemical environment. The affinity of glycinin and the mass adsorbed on silica and cellulose increases (by ca. 13 and 89%, respectively) with solution ionic strength (as it increases from 0 to 100 mM NaCl) due to screening of electrostatic interactions. In contrast, β-conglycinin adsorbs on the same substrates to a lower extent and the addition of electrolyte reduces adsorption (by 25 and 57%, respectively). The addition of 10 mM 2-mercaptoethanol, a denaturing agent, reduces the adsorption of both proteins with a significant effect for glycinin. This observation is explained by the cleavage of disulfide bonds which allows unfolding of the molecules and promotes dissociation into subunits that favors more compact adsorbed layer structures. In addition, adsorption of glycinin onto cellulose decreases with lowering the pH from neutral to pH 3 due to dissociation of the macromolecules, resulting in flatter adsorbed layers. The respective adsorption isotherms fit a Langmuir model and QCM shifts in energy dissipation and frequency reveal multiple-step kinetic processes indicative of changes in adlayer structure.     

Effect of Oxidation of αA- and αB-Crystallins on their Structure, Oligomerization and Chaperone Function

The purpose of this study was to investigate the effect of metal-catalyzed oxidation by H₂O₂ on the structure, oligomerization, and chaperone function of αA- and αB-crystallins. Recombinant αA-and αB-crystallins were prepared by expressing them in E. coli and purifying by size-exclusion chromatography. They were incubated with 1.5 mM H₂O₂ and 0.1 mM FeCl₃ at 37 ^∘C for 24 hrs and the reaction was stopped by adding catalase. Structural changes due to oxidation were ascertained by circular dichroism (CD) measurements and chaperone activity was assayed with alcohol dehydrogenase (ADH) and insulin as target proteins. The oligomeric nature of the oxidized proteins was assessed by molecular sieve HPLC. The secondary structure of the oxidized αA- and αB-crystallins has been substantially altered due to significant increase in random coils, in addition to decrease in β-sheet or α-helix contents. The tertiary structure also showed significant changes indicative of different mode of folding of the secondary structural elements. Chaperone function was significantly compromised as supported by nearly 50% loss in chaperone activity. Oxidation also resulted in the formation of higher molecular weight (HMW) proteins as well as lower molecular weight (LMW) proteins. Thus, oxidation leads to disintegration of the oligomeric structure of αA- and αB-crystallins. Chaperone activity of the HMW fraction is normal whereas the LMW fraction lacks any chaperone activity. So, it appears that the formation of the LMW proteins is the primary cause of the chaperone activity loss due to oxidation.     

Effects of 17β-estradiol on turkey myogenic satellite cell proliferation,differentiation, and expression of glypican-1, MyoD and myogenin

The hypothesis of this study was that 17β-estradiol (estradiol) stimulates turkey skeletal muscle growth by influencing myogenic satellite cell proliferation, differentiation, and the gene expression of selected proteins important in regulating growth and development. Increasing levels of estradiol were administered in basal medium containing additional nutrients. Female-derived pectoralis major (PM) satellite cell proliferation was stimulated by estradiol at a level of 10^? 9 M following 4 days of treatment. Male PM and biceps femoris (BF) satellite cell proliferation was increased at 10^? 12 M estradiol. Turkey embryonic myoblast proliferation, however, decreased with 10^? 9 M and 10^? 5 M estradiol following 3 days under these conditions. Estradiol had no effect on the differentiation of any of the 4 groups of cells. Likewise, glypican-1 expression was unaffected by estradiol treatment. MyoD expression decreased in male PM but not BF cells. MyoD expression in female PM cells and embryonic myoblasts were also unaffected by estradiol administration. Estradiol decreased myogenin expression in male satellite cells, but had no effect on female cells. There was a slight decrease in myogenin expression in embryonic myoblasts. The results demonstrate a direct effect of estradiol on avian satellite cell proliferation independent of glypican-1, and decreased expression of MyoD and myogenin in some myogenic cells, coinciding with increased cellular proliferation.     

Mitochondrial dysfunction and biotransformation of β-carboline alkaloids,harmine and harmaline,on isolated rat hepatocytes

The cytotoxic effects and biotransformation of harmine and harmaline, which are known β-carboline alkaloids and potent hallucinogens, were studied in freshly isolated rat hepatocytes. The exposure of hepatocytes to harmine caused not only concentration (0–0.50 mM)- and time (0–3 h)-dependent cell death accompanied by the formation of cell blebs and the loss of cellular ATP, reduced glutathione, and protein thiols but also the accumulation of glutathione disulfide. Of the other analogues examined, the cytotoxic effects of harmaline and harmol (a metabolite of harmine) at a concentration of 0.5 mM were less than those of harmine. The loss of mitochondrial membrane potential and generation of oxygen radical species in hepatocytes treated with harmine were greater than those with harmaline and harmol. In the oxygen consumption of mitochondria isolated from rat liver, the ratios of state-3/state-4 respiration of these β-carbolines were decreased in a concentration-dependent manner. In addition, harmine resulted in the induction of the mitochondrial permeability transition (MPT), and the effects of harmol and harmaline were less than those of harmine. At a weakly toxic level of harmine (0.25 mM), it was metabolized to harmol and its monoglucuronide and monosulfate conjugates, and the amounts of sulfate rather than glucuronide predominantly increased with time. In the presence of 2,5-dichloro-4-nitrophenol (50 μM; an inhibitor of sulfotransferase), harmine-induced cytotoxicity was enhanced, accompanied by decrease in the amount of harmol-sulfate conjugate, due to an increase in the amount of unconjugated harmol and the inhibition of harmine loss. Taken collectively, these results indicate that (a) mitochondria are target organelles for harmine, which elicits cytotoxicity through mitochondrial failure related to the induction of the MPT, mitochondrial depolarization, and inhibition of ATP synthesis; and (b) the toxic effects of harmine are greater than those of either its metabolite harmol or its analogue harmaline, suggesting that the onset of harmine-induced cytotoxicity may depend on the initial and/or residual concentrations of harmine rather than on those of its metabolites.     

Effects of Moranoline, 4-O-α-D-Glucopyranosylmoranoline and Their N-Substituted Derivatives on Thermostability of Cyclodextrin Glycosyltransferase,Glucoamylase, and β-Amylase

In repeated glycosylmoranolines synthetic reaction at 55°C, cyclodextrin glycosyltransferase (CGT-ase, EC 2.4.1.19) from Bacillus stearothermophilus retained its activity for more than 600 days. A main stabilizing compound. was found to be 4-O-α-D-glucopyranosylmoranoline.

The thermostabilizing activities of moranoline, 4-O-α-D-glucopyranosylmoranoline, and their N-substituted derivatives were studied. Moranoline and its N-substituted derivatives stabilized glucoamylase. 4-O-α-D-Glucopyranosylmoranoline and its N-substituted derivatives stabilized CGT-ase and β-amylase.