As a result of histological and ultracytochemical investiga tions concerning the influence of thiamine and its disulfide derivative, thiamine tetrahydrofurfuryl disulfide (TTFD), on acetylcholinesterase (AChE) in extirpated guinea pig atria, it was found that there was a clear increase in the AChE activity by 10-4 M TTFD, a weak increase with 10-5 M and an extremely weak increase, about the same as that in only the nutrient (Locke's solution), with 5×10-4 M. However, with 10-4 M of thiamine there was a tendency for the activity to be the same degree as with Locke's solution alone or be even inhibited at times.
The in vivo utilization of D-[U-14C] glucose with particular reference to its incorporation into brain and liver proteins was studied in biotin-deficient rats. The data show a significant reduction in the incorporation of glucose carbon into brain and liver proteins. A disturbance in the intermediary metabolism of glucose appears to be one of the factors responsible for the decreased incorporation of the label into proteins in biotin deficiency.
An unidentified factor which can completely replace the vitamin B12 requirement of a protozoan, Ochromonas malhamensis, was found in commercial yeast extract powder. The factor showed a positive sugar test with orcinol reagent. The presence of sulfur was demonstrated with platinic iodide reagent. The molecular weight, 297, and the chemical formula, C11H15O3N5S, were determined by mass spectrometry and elemental analysis. Infra-red and nuclear magnetic resonance studies indicated the presence of a thiomethyl group. The factor was hydrolyzed by treatment with acid into adenine and 5-methylthioribose, i.e., the sugar constituent of 5'-methylthioadenosine. The factor was identified as 5'methylthioadenosine from the behavior exhibited in thin-layer chromatography and from microbiological tests for its vitamin B12-replacing effect.
Serum vitamin E and cholesterol levels were determined for the residents in rural regions of Yamagata Prefecture, Japan. The average serum vitamin E were 0.99±0.25mg/100ml in 166 men, and 1.06±0.26mg/100ml in 178 women. Only 0.6% of the subjects were below 0.5mg/100ml. There was a significant difference between the serum vitamin E levels of men and women. However there were no statistically significant differences among serum vitamin E of various age groups. The best correlation for serum vitamin E was found with serum cholesterol.
The effects of VB6 deficiency on collagen metabolism were studied using young and adult rats. It was observed in VB6 deficient rats, that both the amount of urinary hydroxyproline and salt soluble fraction of skin collagen decreased. Furthermore, decrease of the α-component and increase of the β-com ponent were also found in the soluble collagen. However, the activity of plasma amine oxidase was lower and the aldehyde content in the acid soluble collagen was also lower than the control group. These changes were revealed more clearly in young growing rats than in adult rats. Based on these results, it may be that VB6 participates in the allysine (α-amino-adipic-δ-semialdehyde) formation which is considered as the first step of collagen maturation and also in the synthesis of protocollagen peptide chains.
The addition of caffeine caused the accumulation of a new nucleotide compound simultaneously with the rigid inhibition of ribo flavin production in non-growing cells of Eremothecium ashbyii. In the present study we tried to identify the structure of the nucleotide compound using non-growing cells of the mold. 1) It became possible to obtain a large amount of mycelia by massculti vation in a reagent tank. 2) A new nucleotide compound, referred to as compound A in the paper, was extracted with perchloric acid solution and purified by the following subsequent procedures: 1) Dowex 1×2 (HCOO-) column, 2) charcoal treatment, 3) DEAE-Sephadex A25 (Cl-) column, 4) Dowex 1×2 (Cl-) column, and 5) DEAE-Sephadex A25 (HCO3-) column. 3) The structure of the new nucleotide compound was proved to be guanine ribonucleotidyl-(3'-5')-adenosine (GpA) from the results of the following analyses: 1) alkaline degradation, 2) UV-spectra, IR-spectra and NMR-spectra, and 3) enzymatic treatments with RNase T2 and phosphodiesterase. 4) The roles of caffeine and guanine ribonucleotidyl-(3'-5')-adenosine in connection with flavinogenesis of this mold were discussed.
Newly weaned male rats were maintained on a riboflavinfree diet for 5 weeks, and a study was made on the effect of the deficiency upon liver lipids. The content of glyceride in the livers varied among the deficient rats. High contents of glyceride were demonstrated in one-third of the deficient rats, whereas the similar level as that of control was shown in the remaining deficient rats. Contents of phospholipids and relative amounts of individual phospholipids were not altered significantly by the deficiency. Riboflavin deficiency exerted effects on fatty acid components of liver lipids. The composition of fatty acids of triglycerides varied in the deficient rats depending on the content of glycerides. However, trends of increase in linoleic acid and decrease in palmitic acid towards fatty liver were observed in the deficiency in comparison with the control. On the other hand, the changes in phospholipid fatty acids were similar in all deficient rats, and the increase in linoleic acid and the decrease in arachidonic acid were brought about by the deficiency compared with controls, respectively. In liver homogenates, the incorporation of 14C-palmitate into triglycerides was higher in the deficient rats irrespective of the presence or absence of fluoride, but incorporation into phospholipids was slightly lower in the deficient rats than in control animals.
Absorption β-alanine, anserine or carnosine from rat intestine was studied in vivo by a force feeding method and in vitro using an everted sac method. Possibility of anserine and carnosine hydrolysis prior to intestinal absorption was also investigated using a glycylleucine dipeptidase-containing fraction prepared from rat intestine. The following results were obtained. 1) Anserine and carnosine were absorbed as they were from rat small intestine. 2) Both anserine and carnosine were partially hydrolyzed in vitro by the glycylleucine dipeptidase-containing fraction. Carnosine was hydro lyzed faster than anserine. The above rather confilicting results suggest that physiological amounts of anserine and carnosine might be absorbed from rat small intestine in dipeptide forms.
Alanine metabolism in normal and pyridoxine-deficient rats was studied in vivo and in vitro. Incorporation of 14C-alanine into various liver components was determined and no difference was shown between normal and deficient animals in the incorporation into liver homogenates, lipid, protein and plasma glucose. Using the liver slice system, gluconeogenic activity from alanine or pyruvate was 40% lower in deficient rats compared with the activity of normal rats. However, inhibition was completely removed by the addition of 2-oxoglutarate to alanine. Penicillamine did not affect glucose formation from alanine in the liver slice.
1. In this study, the carnitine level in 24-hr urine has been determined in males, (a) before and after a single oral dose of 500 mg (as carnitine) of DL-carnitine chloride, (b) during fasting, and (c) before and after a severe running program (3×2, 000m/8-8.5 min). 2. After the administration of DL-carnitine chloride, the urinary carnitine excretion was increased by only approximately 10% of the dose, suggest ing a large body pool size of carnitine. 3. Urinary carnitine excretion was significantly increased during five-day fasting; a maximum level of 2.17±0.24 (mean and SD) mmoles/day was 4.6 times higher than the usual level of 0.47±0.10 mmloes/day (p<0.001). Respiratory quotients (RQ) decreased significantly (p<0.01) from the control value of 0.81±0.03 to the value of 0.75±0.02 after five-day fasting and was significantly correlated with urinary carnitine levels (r=-0.62, p<0.05). 4. The urinary excretion of carnitine increased slightly with heavy running exercise. 5. The results are discussed in relation to the physiologic regulation of the rate of carnitine synthesis.