Alterations in the metabolic and cardiorespiratory response to exercise in Huntington's Disease.

BACKGROUND: Limited data suggests that an altered metabolic and cardiorespiratory exercise response may affect exercise performance in individuals with Huntington's disease (HD). There is no clear exploration of the response in individuals at different stages of the disease or in relation to genetic markers. This study aimed to examine the exercise response and recovery of HD participants, and the relationship to genetic and clinical markers. METHOD: HD gene-positive participants (n = 31; 9 pre-manifest; 22 manifest HD) and a healthy control group (n = 29) performed an incremental exercise test until exhaustion. Performance, cardiorespiratory, metabolic and perceptual responses to exercise were determined from a maximal cycle ergometer test throughout the exercise test and during a recovery period. RESULTS: During sub-maximal exercise, metabolic (lactate levels, oxygen uptake) and cardiorespiratory markers (heart rate) were elevated in HD participants compared to controls. Lactate elevation was specific to pre-manifest HD participants. Work capacity was reduced in both pre-manifest and manifest HD participants with tests terminated with no difference in metabolic, perceptual or cardiorespiratory markers. Submaximal oxygen uptake was correlated with motor score, whilst peak measures were unrelated to genetic or clinical markers. Heart rate recovery was attenuated in pre-manifest and manifest HD participants. CONCLUSIONS: Our findings confirm metabolic and cardiorespiratory deficits reduce exercise performance and affect recovery from an early stage in HD, with submaximal deficits related to phenotypic expression. Exercise capacity appears to be limited by an altered movement economy, thus clinicians should consider an altered exercise response and recovery may affect prescription in HD.

A high-mobility-group protein and its cDNAs from Drosophila melanogaster.

We have identified, purified, and characterized a high-mobility-group (HMG) protein and its cDNAs from Drosophila melanogaster. This protein, HMG D, shares most of the characteristics of vertebrate HMG proteins; it is extractable from nuclei with 0.35 M NaCl, is soluble in 5% perchloric acid, is relatively small (molecular weight of 12,000), has both a high basic (24%) and high acidic (24%) amino acid content, and is a DNA-binding protein. HMG D exhibits characteristics of both the vertebrate HMG 1 and 2 class and the HMG 14 and 17 class of proteins. Its amino acid sequence is similar (36% amino acid identity) to that of HMG1, while its size and selective extraction with ethidium bromide are similar to properties of the HMG 14 and 17 class of proteins. HMG D is encoded by a single-copy gene that maps to 57F8-11 on the right arm of chromosome 2. Two transcripts are observed during embryogenesis; the protein is relatively stable throughout development. By the biochemical criteria of size, solubility, and amino acid content, HMG D appears to be the major HMG protein of D. melanogaster.

Elevated levels of polyamines and histamine in adenocarcinomas of the thyroid.

The concentrations of polyamines (putrescine, spermidine, and spermine) and of histamine in normal and diseased thyroids were determined with an automated amino acid analyzer. A total of 39 specimens was investigated: 7 specimens of normal tissue, 6 adenocarcinomas, 2 specimens of tissues adjacent to adenocarcinoma, 13 specimens from treated Graves' disease, 7 follicular adenomas, 2 adenomatous goiters, and 2 specimens of Hashimoto's thyroiditis. Mean putrescine levels in tissues from normal thyroid, adenocarcinomas, Graves' disease, and follicular adenoma were 26, 143, 20, and 12 nmol/g wet tissue, respectively. The mean levels of both spermidine and spermine were slightly but significantly higher in adenocarcinomas than in other thyroid tissues. The molar ratio of spermidine to spermine was about 0.5 both in the normal and diseased thyroid tissues, except for specimens of thyroiditis. Histamine was detected in 3 of the 6 cases of thyroid carcinomas, and in case of adenomatous goiter. The data suggest that measurement of polyamines, especially putrescine, may be useful for diagnosis of thyroid adenocarcinomas.

Expression of the Bombyx mori beta-tubulin-encoding gene in testis.

We have isolated a beta-tubulin-encoding cDNA clone of Bombyx mori from testes and determined the nucleotide sequence. Northern analyses showed that its expression is testis-specific and most active in the pupal stage.

Isolation of deuterated histones from yeast grown on media dissolved in 2H2O.

We have succeeded in growing Saccharomyces cerevisiae (baker's yeast) on media containing 2H2O and isolating the core histones highly deuterated in the non-exchangeable positions. The deuterated histones obtained here are of great value for their possible widespread use for structural studies of chromatin.

Gel electrophoresis and gel chromatography of calf thymus histones in the presence of a cationic surfactant.

Five histone molecular species, H1, H2A, H2B, H3, and H4, of calf thymus were subjected to gel electrophoresis and gel chromatography in the presence of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), and their behavior was compared with that in the presence of an anionic surfactant, sodium dodecyl sulfate (SDS). In the presence of CTAB, the retardation coefficient (KR) and distribution coefficient (Kd) values calculated for the five histone species were linearly related to their molecular weights, without showing abnormality of the type found in the presence of SDS. It was concluded that CTAB-gel electrophoresis is useful for the analysis of histones.

High mobility group nonhistone chromosomal proteins also exist in Tetrahymena.

High mobility group (HMG) nonhistone chromosomal proteins have been shown to exist also in the ciliated protozoan Tetrahymena pyriformis. One or two histone-like components were extracted with 0.25 M HCl from the chromatin, in addition to five histone species. These proteins were also extracted selectively with 0.5 M HClO4, 0.35 M NaCl, or 4 mM spermidine, together with H1 histone, and were characterized as HMG proteins on the basis of the following criteria: high mobilities on polyacrylamide gel electrophoresis, relatively low molecular weights, amino acid compositions rich in lysine and glutamic acid, and relative contents in chromatin. This extends the distribution of the HMG proteins to all four eukaryotic kingdoms, and suggests the possibility that they have some universal role in chromatin structure and function.

Effects of triton X-100 on gel electrophoresis and gel chromatography of histones. Possible binding to helical regions.

Polyacrylamide gel electrophoresis of whole histones of calf thymus, chicken erythrocytes, and Tetrahymena was carried out in the absence or presence of a nonionic surfactant, Triton X-100 (up to 6 mM), in 0.9 M acetic acid and 6.25 M urea-0.9 M acetic acid. Calf thymus whole histone was also chromatographed on Bio-Gel P-200 in the absence or presence of 6 mM Triton in 0.01 M HCl and 8 M urea-0.9 M acetic acid. Triton reduced the electrophoretic mobility and distribution coefficient of various histone species in the following order of decreasing effect; H2A greater than H3, H4 greater than H2B greater than H1 in the absence of urea. H1 and specific histones for chicken erythrocytes and Tetrahymena were almost unaffected. Urea antagonized the surfactant effect more for H4 and H2B, and less for H2A and H3. Such surfactant effects can be correlated with the helical contents of histone species under the experimental conditions used, rather than their total hydrophobicites, suggesting that Triton binds to helical regions.

Widespread occurrence of norspermidine and norspermine in eukaryotic algae.

Seven phyla of eukaryotic algae were analyzed to determine their contents of diamines and polyamines. The algae examined included Rhodophyta, Pyrrophyta, Chrysophyta, Phaeophyta, Euglenophyta, Chlorophyta, and Charophyta. Both putrescine and spermidine were detected in all the algae studied, while appreciable amounts of spermine were detected only in a few species of algae. 1,3-Diaminopropane, norspermidine, and norspermine, which are chemical analogs of putrescine, spermidine, and spermine, respectively, were widely distributed in various species of algae. There was no parallelism between the distribution patterns of putrescine derivatives and those of 1,3-diaminopropane derivatives. Cadaverine and agmatine were detected in multicellular marine algae. Homospermidine was detected sporadically in some algae. The biological and phylogenetical significance of polyamines in these lower eukaryotes is discussed.

Unusual polyamines in slime molds Physarum polycephalum and Dictyostelium discoideum.

We analyzed the cellular contents of not only major polyamines but also minor polyamines in slime molds Physarum polycephalum and Dictyostelium discoideum. The presence of putrescine and spermidine in either plasmodia or myxamoebae of these molds as major polyamines was confirmed. In addition to these polyamines, appreciable amounts of 1,3-diaminopropane were detected in P. polycephalum and D. discoideum. Cadaverine and sym-homospermidine were detected in P. polycephalum even when the slime mold was cultured in a chemically defined growth medium. Spermine was not detected when these molds were grown in synthetic media. Other "unusual" polyamines such as norspermidine, norspermine, thermospermine, aminopropylcadaverine, and canavalmine were not detected in either mold.

Further study on polyamines in primitive unicellular eukaryotic algae.

The possible usefulness of polyamines as chemotaxonomic markers has been investigated in eukaryotic algae. Polyamines were analyzed in 12 species of primitive unicellular eukaryotic algae including some anomalous species. Norspermidine and norspermine in addition to putrescine and spermidine are widely distributed in most unicellular species of the algae. However, neither norspermidine nor norspermine was found in the taxonomically conflicting algae, Cyanophora and Glaucocystis, which contain cyanellae, or in a primitive red alga, Porphyridium. A thermoacidophilic eukaryotic alga, Cyanidium, is rich in both norspermidine and norspermine. Appreciable amounts of spermine and sym-homospermidine were detected only in the species belonging to the Rhodophyta (red algae).

Distinct difference in the polyamine compositions of bryophyta and pteridophyta.

Polyamine contents of various species of plants and fungi including Bryophyta, Pteridophyta, Gymnospermae, Ascomycota, Basidiomycota, and Lichenobionta were determined by the combination of six chromatographic techniques. Polyamines examined included putrescine, spermidine, spermine, 1,3-diaminopropane (diaminopropane), sym-norspermidine (norspermidine), sym-norspermine (norspermine), thermospermine, caldopentamine, homocaldopentamine, cadaverine, aminopropylcadaverine, sym-homospermidine (homospermidine), agmatine, and canavalmine. In addition to the widely occurring polyamines (putrescine, spermidine, and spermine), the "unusual" polyamines norspermidine and norspermine were found to be widely distributed in Bryophyta and Lichenobionta. These two polyamines were not detected in any species of Pteridophyta, Gymnospermae, and fungi even though their possible precursor, diaminopropane, was found in some species. Homospermidine was one of the major polyamines in Bryophyta and Lichenobionta, and was detected in most species of Pteridophyta and sporadically in higher plants. Agmatine was detected in most species of Bryophyta and in certain species of Gymnospermae. These data suggest that norspermidine, norspermine, and homospermidine can serve as chemical phylogenic and taxonomic markers in Plantae and Fungi.

Changes in polyamine levels in various organs of Bombyx mori during its life cycle.

Polyamines in various organs of larval, pupal, and moth stages of Bombyx mori, were assayed by high-performance ion-exchange chromatography and paper and thin-layer chromatography. Putrescine and spermidine were especially abundant in the silk gland, gonads, mucous gland, and sucking stomach; spermine was also present in them, but at much lower concentrations. Both norspermidine and norspermine were detected in almost all organs examined, while their precursor 1,3-diaminopropane was found only in a limited number of organs. Low concentrations of sym-homospermidine were observed in the silk gland and ovary. Cadaverine content was particularly high in the mucous gland which contained diapause eggs and the sucking stomach. Diapause eggs contained much higher levels of cadaverine than non-diapause eggs. The concentrations of most polyamines in the silk glands remained rather constant during the larval stage, and decreased markedly at the pupal stage. Polyamines in gonads, in contrast, did not decrease at the pupal stage, but putrescine, diaminopropane, and norspermidine rather increased during the pupal and moth stages.

Polyamine distributions in thermophilic eubacteria belonging to Thermus and Acidothermus.

Triamines such as norspermidine, spermidine, and homospermidine and tetraamines such as norspermine, spermine, thermospermine, and aminopropylhomospermidine were found to be distributed ubiquitously in the eight extremely thermophilic (growing at 70 degrees C) Thermus species tested. Three linear pentaamine (caldopentamine, homocaldopentamine, and thermopentamine), two linear hexaamines (caldohexamine and homocaldohexamine), two tertiary branched tetraamines (N4-aminopropylnorspermidine and N4-aminopropyl-spermidine), and quaternary branched pentaamines such as N4-bis(aminopropyl)norspermidine and N4-bis(aminopropyl)spermidine were detected in T. thermophilus HB8, T. filiformis Wai33 A1, T. flavus AT-62, and T. caldophilus GK24. The linear hexaamines and branched polyamines were absent in T. aquaticus YT-1, T. sp. X-1, T. sp. T2, and T. sp. T351, in which linear pentaamines were minor components. Moderately thermophilic Thermus ruber and Thermus sp. K-2 contained putrescine, spermidine, norspermidine, homospermidine, spermine, norspermine, thermospermine, and aminopropylhomospermidine. No pentaamines, hexaamines, or branched polyamines were found in these two moderately thermophilic Thermus species. On the other hand, moderately thermophilic, acidophilic Acidothermus cellulolyticus was devoid of all the polyamines.

Polyamines in photosynthetic eubacteria and extreme-halophilic archaebacteria.

Qualitative and quantitative determinations of polyamines have been done in 4 photosynthetic eubacteria and 6 extreme-halophilic archaebacteria. For comparison, 5 moderate-halophilic eubacteria were also analyzed to determine their polyamine contents. Not only putrescine and spermidine but also homospermidine were found in the photosynthetic eubacteria, especially in the N2-fixing species, Rhodospirillum and Chromatium. Norspermidine, norspermine, and spermine were not detected in the phototrophic eubacteria. No appreciable amount of any polyamine was found in extreme-halophilic archaebacteria, Halobacterium and Halococcus, while moderate-halophilic eubacteria contained quite high concentrations of putrescine and spermidine and cadaverine. When arginine was incubated with cell lysates of these two archaebacteria, appreciable amounts of agmatine were produced; neither putrescine nor cadaverine was formed in the presence of ornithine or lysine. No detectable amount of spermidine was produced by the lysates on incubation with putrescine.

Glucocorticoids suppress and oestrogens enhance the lipopolysaccharide-induced increase in putrescine and N1-acetylspermidine in mouse liver.

Previously we reported that administration of lipopolysaccharide (LPS) to mice increased the hepatic levels of putrescine (PUT) and N1-acetylspermidine (N1-acetyl-SPD). In the current study, we examined the in vivo effects of some steroid hormones on the LPS-induced increase in PUT and N1-acetyl-SPD. Corticosterone, hydrocortisone and dexamethasone suppressed the LPS-induced increase in PUT and N1-acetyl-SPD in mouse liver in a dose-dependent manner, dexamethasone being the most effective among them. On the other hand, oestrone and oestradiol-17 beta enhanced the LPS-induced increase in PUT and N1-acetyl-SPD in a dose-dependent manner. Oestradiol-17 alpha and 16 beta-ethyl-oestradiol, as an inactive oestradiol isomer and an antioestrogen, respectively, likewise enhanced the increase in PUT and N1-acetyl-SPD concentrations induced by LPS. 16 alpha-hydroxy-oestradiol (oestriol), 16 alpha-hydroxyestrone, 2-hydroxyoestradiol, 2-hydroxyoesterone, progesterone, testosterone, diethylstilboestrol and nonsteroidal antioestrogens such as tamoxifen and nafoxidine had no effect on the increase. Oestradiol-17 beta enhanced and corticosterone had little effect on the carbon tetrachloride-induced increase in PUT and N1-acetyl-SPD. These results suggest that glucocorticoids suppress the increase by preventing the immunological injury by Kupffer cells on hepatocytes and that the stimulatory effect of oestrogens may not be associated with their oestrogenic activities mediated by the oestrogen receptor system.

Interconversion of polyamines in wild-type strains and mutants of yeasts and the effects of polyamines on their growth.

Yeasts of wild-type strains, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Candida albicans were shown to have the ability to form aminopropylcadaverine and aminopropylhomospermidine from cadaverine and homospermidine, respectively. A polyamine autotroph S. cerevisiae 179-5, which lacks ornithine decarboxylase, produced both aminopropylcadaverine and aminopropylhomospermidine, while another mutant S. cerevisiae Y 260 A, which lacks spermine synthase, formed only aminopropylcadaverine. Naturally-occurring triamines and tetraamines except norspermidine and norspermine stimulated the growth of S. cerevisiae 179-5. All the six aliphatic diamines with carbon chain length ranging from one to six were effective in activating the growth of S. cerevisiae 179-5, though all of them were not converted to either triamines or tetraamines.

Superoxide dismutase and alpha-tocopherol suppress the paraquat-induced elevation of N1-acetylspermidine and putrescine in primary culture of adult rat hepatocytes.

A transient increase in N1-acetylpolyamines and putrescine (PUT) was observed in hepatocytes at the early stage of primary culture of rat hepatocytes. After pre-culture for 36 hr when the polyamine content returned to constant levels, we tested the effects of superoxide dismutase (SOD) and alpha-tocopherol on the paraquat-induced increase in N1-acetylspermidine (N1-acetyl-SPD) and PUT in the culture. Paraquat increased (N1-acetyl-SPD in a dose-dependent manner. It also increased PUT at doses between 0.1 and 1.3 mM. Both SOD and alpha-tocopherol suppressed the increase in N1-acetyl-SPD and PUT induced by paraquat. These results suggested that superoxide anion is one of the factors which increase N1-acetyl-SPD and PUT in hepatocytes. Lipopolysaccharide (LPS) little affected the polyamine concentration in the cultured hepatocytes, though it increases polyamine in mouse liver when given in vivo. These findings suggested that the formation of superoxide anion after administration of LPS in vivo is mediated by Kupffer cells.

Decrease in myocardial polyamine concentration in rats with myocardial infarction.

Cardiac polyamines are thought to protect the myocardium against harmful stimuli and to be regulated by sympathetic nerve activation. In the present study, polyamines concentrations in non-infarcted myocardium were investigated. Myocardial polyamines contents decreased significantly in the non-infarcted regions by day 3 in rats with myocardial infarction compared with sham-operated rats and with the untreated control rats. The cardiac catecholamine concentration decreased by day 1 after myocardial infarction. Myocardial ornithine decarboxylase activity also decreased in the non-infarcted regions; suggesting that the decrease in cardiac polyamines contents relate to an insufficiency of the ornithine decarboxylase activity in rats with myocardial infarction. These results suggest that the decrease in polyamines concentrations after myocardial infarction is associated with functional sympathetic nerve denervation and that the vulnerability of the heart after myocardial infarction may be due to a decrease in polyamine concentrations in the non-infarcted region.