Variation among chicken stocks in the fractional rates of muscle protein synthesis and degradation

Fractional rates (% · day^–1) of synthesis and degradation were determined by measuring the output of N-methylhistidine (MeHis) in the excreta at 4 and 8 weeks of age in the chicken. At 4 weeks of age, the fractional rate of synthesis of the meat-type stock was twice that of the egg-type stock (White Leghorn), but the fractional rates of synthesis at 8 weeks of age were similar (4.1–5.1% · day^–1) among stocks. The fractional rate of degradation (1.3–1.5% · day^–1) of the meat-type stock at 8 weeks of age was less than half the rate of the egg-type stock (2.9% · day^–1). The fractional rates of synthesis and degradation at 4 weeks of age in the Satsuma native fowl were relatively high compared with those in the other stocks. In particular, the rate of degradation (8.6% · day^–1) at 4 weeks of age was approximately twice that of other stocks. These results show that fractional rates of synthesis and degradation of muscle protein in the chicken differ among genetically diverse groups. The effect of changes in rates of synthesis and degradation on the change in fractional growth rate also differed. From regression coefficients (b_{K s · FGR} and b_{K d · FGR}) of these rates in skeletal muscle protein on the fractional growth rate, it was recognized that the change in growth rate accompanies the changes in both synthesis and degradation in White Leghorn and commercial broilers but only the change in synthesis in White Plymouth Rock (dw) and Satsuma native fowl.     

A high-throughput screen for inhibitors of the prolyl isomerase,Pin1, identifies a seaweed polyphenol that reduces adipose cell differentiation

The peptidyl prolyl cis/trans isomerase Pin1 enhances the uptake of triglycerides and the differentiation of fibroblasts into adipose cells in response to insulin stimulation. Pin1 downregulation could be a potential approach to prevent and treat obesity-related disorders. In order to identify an inhibitor of Pin1 that exhibited minimal cytotoxicity, we established a high-throughput screen for Pin1 inhibitors and used this method to identify an inhibitor from 1,056 crude fractions of two natural product libraries. The candidate, a phlorotannin called 974-B, was isolated from the seaweed, Ecklonia kurome. 974-B inhibited the differentiation of mouse embryonic fibroblasts and 3T3-L1 cells into adipose cells without inducing cytotoxicity. We discovered the Pin1 inhibitor, 974-B, from the seaweed, E. kurome, and showed that it blocks the differentiation of fibroblasts into adipose cells, suggesting that 974-B could be a lead drug candidate for obesity-related disorders.     

Preparation of poly(L-lactide)-based microspheres having a cationic or anionic surface using biodegradable surfactants

Poly(L-lactide)-based microspheres having cationic or anionic surfaces were prepared using polydepsipeptide-block-poly(L-lactide)s as surfactants. Polydepsipeptide-block-poly(L-lactide)s having amino or carboxylic acid groups on their side chains were synthesized through anionic ring-opening polymerizations of L-lactide using the corresponding protected polydepsipeptides as macroinitiators and consequent deprotections. Since these amphiphilic copolymers consisting of hydrophobic segments and hydrophilic segments with amino or carboxylic acid groups could be converted to cationic or anionic block copolymers, they could act as surfactants preparing poly(L-lactide)-based microspheres by an oil-in-water emulsion method. The amount of ionic groups located on the surfaces of the obtained microspheres was found to increase with increasing the feed of charged polydepsipeptide-block-poly(L-lactide)s in the blend of poly(L-lactide) and block copolymers. The average diameters of the dried microspheres estimated by scanning electron microscopy were found to decrease with an increase in feed of block copolymers in polymer blends.     

A hyperosmotic stress-induced mRNA of carp cell encodes Na(+)- and Cl(-)-dependent high affinity taurine transporter

A cDNA clone encoding a Na(+)- and Cl(-)-dependent high affinity taurine transporter was isolated from a common carp cell line, Epithelioma papulosum cyprini (EPC), as a hyperosmotic stress-inducible gene by RNA arbitrarily primed PCR. The clone contained a 2.5-kb cDNA fragment including an open reading frame of 1878 bp encoding a protein of 625 amino acids. The deduced amino acid sequence of carp taurine transporter shows 78-80% identity to those of cloned mammalian taurine transporters. The functional characteristics of the cloned transporter were analyzed by expression in COS-7 cells. Transfection with the cDNA induced Na(+)- and Cl(-)-dependent taurine transport activity with an apparent K(m) of 56 microM. The Na(+)/Cl(-)hepatopancreas. Taurine transporter mRNA level increased up to 7.5-fold on raising the ambient osmolality from 300 to 450 mosmol/kgH(2)O. These data suggest the significant role of taurine as an osmolyte in carp cells.     

More than a 600-fold variation in nitrogen dioxide assimilation among 217 plant taxa

Assimilation of nitrogen dioxide in response to fumigation with ¹⁵N-labelled nitrogen dioxide was studied in 217 plant taxa. The taxa included 50 wild herbaceous plants collected from roadsides (42 genera, 15 families), 60 cultivated herbaceous plants (55 genera, 30 families) and 107 cultivated woody plants (74 genera, 45 families). Two parameters, the 'NO₂-N content', or NO₂-derived reduced nitrogen content in fumigated plant leaves (mg N g^–1 dry weight), and the 'NO₂-utilization index', or percentage of the NO₂-derived reduced nitrogen in the total reduced nitrogen, were determined. The NO₂-N content differed 657-fold between the highest ( Eucalyptus viminalis ; 6·57) and lowest ( Tillandsia ionantha and T. caput-medusae ; 0·01) values in the 217 taxa; 62-fold in a family (Theaceae) and 26-fold in a species ( Solidago altissima ). Nine species had NO₂-utilization indices greater than 10%, of which Magnolia kobus , Eucalyptus viminalis , Populus nigra , Nicotiana tabacum and Erechtites hieracifolia had NO₂-N contents > 4·9. These plants can be considered 'NO₂-philic' because in them NO₂-nitrogen has an important function(s). The Compositae and Myrtaceae had high values for both parameters, whereas the monocots and gymnosperms had low ones. These findings suggest that the metabolic pathway of NO₂-nitrogen differs among plant species. The information presented here will be useful for creating a novel vegetation technology to reduce the atmospheric concentration of nitrogen dioxide.     

Identification of viral induced genes in Ig+ leucocytes of Japanese flounder Paralichthys olivaceus, by differential hybridisation with subtracted and un-subtracted cDNA probes

Up-regulated genes of leucocytes expressing immunoglobulin (Ig+ leucocytes) of hirame rhabdovirus (HRV)-infected Japanese flounder were identified by differential hybridisation, using subtracted and un-subtracted cDNA probes. Ig+ leucocytes were separated from apparently healthy and HRV-infected Japanese flounder by the magnetic beads antibody method using mouse anti-Japanese flounder Ig monoclonal antibody (mab). A cDNA library was constructed from HRV-infected Japanese flounder leucocytes, and was screened with subtracted cDNA probes enriched in genes up-regulated by HRV infection. Fifty cDNAs were isolated for further analysis. These included cDNAs coding for homologues of interferon-inducible 56K protein (IFI56), Stat3, CEF-10, RGS5, inducible poly(A) binding protein, prolylcarboxylpeptidase, basigin III (Ig superfamily), MUC-18 (Ig superfamily), proteasome-nexin 1 (SERPIN), herpes virus entry mediator (TNFR family), collagenase III, gelatinase-b, megakaryocyte stimulating factor, Rab8-interacting protein, IgM, IgD and 20 unknown cDNA clones. The majority of these identified genes are reported for the first time in fish. From leucocytes mRNA for homologues of IFI56, CEF-10, Stat3, SERPIN and inducible poly (A) binding protein expression was shown to increase following HRV infection.     

An immunohistochemical study of serotonin-containing nerves in the colon of rats

The localization of the serotonin-like immunoreactive nerves of the rat colon was investigated by means of immunohistochemistry, utilizing an antibody against serotonin. In non-treated colons, serotonin-positive neuropils were consistently detected around the myenteric plexus. In pargyline-treated colons, serotonin-like fibres were demonstrated in association with either the small intramural blood vessels of the submucosa or the extramural nerve bundles. Treatment with 5-hydroxytryptophan (5-HTP) permitted the visualization of additional serotonin-immunoreactive fibres around the large extramural blood vessels. Immunoreactive nerve cell bodies were demonstrated in the myenteric plexus of colons treated with 5-HTP or colchicine. From these observations, it is suggested that the serotoninergic nerves of the rat colon comprise both intrinsic and extrinsic elements.     

The possible existence of a heat-stable alkaline proteinase (HAP) in rat skeletal muscle

1. A unique caseinolytic activity was found in the crude extract from chicken and rat skeletal muscle. Hardly any activity was detected at physiological assay temperatures at pH 8.0 but did well at around 60 degrees C. 2. The activity partially purified from rat skeletal muscle showed optimum pH at around 8.0 at 60 degrees C. It hardly hydrolyzed casein below 50 degrees C, but in the presence of 5 M urea it showed relatively high activity at 30 degrees C. The activity was completely stable at 50 degrees C for 1 hr. 3. The activity seems to be contained in a high mol. wt (450,000) protein from the elution volume and is due to cysteine proteinase from the effect of inhibitors. 4. The above properties agreed with those of the heat-stable alkaline proteinase (HAP) of fish purified homogeneously by electrophoresis. This seems to suggest that HAP may also exist in rat skeletal muscle.     

Effects of carp serum on the growth of goldfish fin cells in early passage

The culture medium supplemented with carp serum and fetal bovine serum (FBS) promoted cell growth significantly and induced morphological change of goldfish fin cells in early passage as compared to the medium containing FBS alone. However, these effects were not observed in RBCF-1, a cell line established from the goldfish fin. The sensitivity of the cells in early passage to carp serum suggests the following possibilities: (1) cells in early passage retain the ability to respond to growth-promoting factors specifically included in carp serum; and (2) this ability is lost during the process of long-term culture and/or long-term culture in FBS eliminates cell groups showing high dependency of cell growth on carp serum.     

Immunohistochemical, in situ hybridization and biochemical studies on endogenous cellulase of Corbicula japonica

We previously reported on the endogenous cellulase gene of Corbicula japonica, CjCel9A. In this study, the tissue localization of the mRNA and translated products of CjCel9A was investigated in order to understand how this gene is physiologically involved in cellulose decomposition by C. japonica. Antiserum against recombinant CjCel9A protein was prepared. Multiple bands were observed mainly on western blot analysis of the crystalline style, and the band sizes partially corresponded to the active bands detected using zymographic analysis. In situ hybridization and immunohistochemical analyses clarified the exclusive production and secretion of this cellulase by the secretory cells localized in the epithelium of the digestive tubules in the digestive gland. These data strongly support our previous assumption that the endogenous cellulase of C. japonica is produced in the digestive gland and transported to the crystalline style to act as a component of its cellulolytic activity.