[in Japanese]

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We have established some suitable conditions for electrophoretic HDL-cholesterol determination using cellulose acetate membrane and investigated their reproducibility.
Also, we have compared this method with some of the precipitation methods.
This method has some merits, such as a precise determination of each cholesterol fraction and very little sample size required.
From these data, it is suggested that this method proves to be an effective method for HDL-cholester61 determination.

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A simple direct colorimetric method was developed for the quantification of serum total bile acids. Two tenth ml of serum was mixed with 10g/L oxamic acid solution. After 5min. incubation at room temperature, to the solution were added 3x-Hydroxy steroid: NADoxidoreductase (3α-HSD), NAD, Diaphorase and Nitrotetrazolium Blue(NTB). The mixture was incubated at 37° for 8min, then the color of resultant Formasan was measured at 540nm.
A linear relationship was obtained between the amount of bile acids and the optical densities in the range 1 to 100μmol/L. The recovery of bile acids added to the serum was 91±10%. The precision of day to day was 10μmol/L with standard deviation of±0.50 and C. V. of 5.0%. The concentration of bile acids in normal fasting sera was less than 6μmol/L.

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Separation and quantitation of 7 tryptophan metabolites in human serum within 50 minutes could be accomplished by high-performance liquid chromatography, with a fluorescence spectrophoto-meter as a detector. 0.6 molar acetate buffer (pH 3.8-6.5) was used for elution in a cation exchange column. Free and protein bound tryptophan metabolites in uremic and normal sera were measured by this method, and it was found that the concentration of free tryptophan in uremic serum was higher than in the normal while the concentration of total tryptophan was lower. ln all uremic sera, β-indole acetic acid and 5-hydroxyindole acetic acid were detected. and in some cases, 5-hydroxy tryptophol and N-acetyl tryptophan were also found. β-lndole acetic acid and 5-hydroxy indole acetic acid were found not only as free forms but also as protein bound forms. None of these indole compounds were detected in normal serum.

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A new method was devised for determination of serum steroid hormorles having the4-en-3-one structure by high Performance liquid chromatography.
The devised technique involves the gradient elution with CH₂Cl₂-C₂H₅OH-H₂O (98.8:1.0:0.2 and 89.7:10.0:0.3) on a column of Zorbax Sil monitoring the absorbance at 254nm.
Thus a synthetic mixture of the structurally related hormones such as progesterone, 4-androstene-3, 17-dione, adrenosterone, deoxycorticosterone, 17α-hydroxyprogesterone, 11β- hydroxy. 4-androstene-3, 17-dione, 11-desoxycortisol, testosterone. corticosterone, cortisone, aldosterone and cortiSol, could be satisfactorily separated.
The Δ⁴-3-ketosteroids were evaluated from the ratio of peak area or peak height to that of prednisolone, an interrlal standard.
For the clinical purposes, serum specimenes of 6 normal male, 5 normale female were sublected to the analysis. The observed value were found in good agreement with the reference values.

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Purified piasma membranes from rat livers were able to take up cholesterol both from serum lipoproteins and cholesterol-hospholipid dispersions in vitro. The cholesterol uptake from liposomes was larger than that from lipoproteins and increased linearly by the increase of choiesterol concentration up to 2μmoles/ml. Although the cholesterol uptake from liposomes was not affected by the heat-inactivation or formalin treatment of the membranes, the uptake from lipoproteins by these denatured membranes was lower than that by the native membranes. The difference between cholesteroi uptake from lipoproteins by the native membranes and that by the denatured membranes is considered to be a process which is mediated by a carrier protein (presumably binding protein to serum lipoproteins) and is saturable with a certain amount of serum lipoproteins at 4°C.
It is suggested that the choiesterol uptakes from low density lipoprotein and high density lipoprotein which are mediated by the specific membrane proteins are larger than those from very low density lipoprotein+intermediate density lipoprotein, but the uptake from high density lipoprotein is brought about by lower affinity binding than those from low and very low+intermediate density lipoprotein fractions.
The cholesterol uptake of hepatic plasma membranes of aged rats from serum lipoproteins by such specific binding was lower than that of young rats, but non-specific uptake of cholesterol from serum lipoproteins and liposomes was almost the same in both membranes.

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The adaptation mechanism of red cell metabolism with special reference to 2, 3-diphosphoglycerate (2, 3-DPG) was studied for tissue anoxia under various disease conditions, i.e. anemia, hypogiycemia and thyroid disorders.
The resuIts were shown as follows:
1. The leveis of red cell 2,3-DPG were significantly increased in arlemia.
The red cell glycolytic enzyme activities were elevated in anemia and were different among various kinds of anemia.
2. In anemic rabbits suffering daily loss of bLood, the 2,3-DPG levels reached a maximum after 2 or 3 days and enzyme activities became elevated after about 2 weeks.
3.2,3-DPG levels were found to be significantly increased in the red cells of normal rabbits incubated in plasma from anemic rabbits though they did not increase in the red cells of anemic rabbits incubated in plasma from normal rabbits, therefore it was considered that there was some mechanism to increase 2,3-DPG in the anemic plasma.
4. Under in vitro examination, erythrocytes cosumed glucose even in a low glucose medium, but stopped consuming glucose in an approximateiy 0.8 mmole glucose concentration. And 2,3-DPG levels fell in a less than 1.9mmole glucose. However, red cell enzyme activities were not significantly changed in a low glucose.
5. No changes in 2,3-DPG levels were found in high glucose medium, but 2,3-DPG levels were found to be lower in the acidotic medium.
6.2,3-DPG levels increased in hyperthyroidism and fell in hypothyroidism. However, no direct effect of T₃ or T₄ on erythrocytes could be found, and no factors regulating 2,3-DPG levels were found in the plasma from patients with hyperthyroidism. A significant correlation was observed between the values of basal metaboiic rate and 2,3-DPG levels in patients with thyroid functlon disorders.
Therefore the author considered that the high levels of 2,3-DPG in hyperthyroid cases were due to increased glycolytic metabolism in erythrocytes resulting from the adaptation mechanism in peripheral tissue anoxia, caused by their increased metabolism which was in turn induced by thyroid hormones.

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Conditions for chemiluminescence reaction of luminol-K₃Fe (CN) 6-hydrogen peroxide mixtures have been investigated using an ATP photometer.
The following procedure for the measurement of hydrogen peroxide by luminol chemiluminescencence reaction was proposed.
1) For the measurement of hydrogen peroxide in the range of concentrations between 4.4μmol/L and 88μmol/L: Mix 20μl of samples with 100μl of 0.01mmol/L luminol in a 0.1mol/L H₃BO₃·KOH solution (pH11.5). Immediatly after mixing, add 100μ/l of 2mmol/L K₃Fe (CN) 6 to the mixture and stand for 15 sec. Then, measure integrated intensity of luminescence for 1min.
2) For the measurement of hydrogen peroxide in the range of concentrations between 8.8μmol/L and 880μmol/L: Mix 20μl of samples with 100μl of 0.2mmol/L luminol in a 0.1 mol/L H₃BO₃·KOH solution (pH 11.5). Immediatly after mixing, add 100μl of 4mmol/L K₃Fe (CN) 6 to the mixture and stand for 15sec. Then, measure integrated intensity of luminescence for 1min. Using these procedure, the error of measurement of hydrogen peroxide were within ±2%.

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Serum lipid concentrations of adult-onset diabetes treated with diet, drug or insulin, were identical to those of healthy subjects with muched age. Serum low density lipoprotein (LDL) concentrations of these patients were howevea higher than those of the controls and serum high density lipoprotein (HDL) showed the tendency to be low when compared with the healthy subjects. Particularly, those who had the history of ischemic heart disease or obesity, had low HDL concentrations. Serum malondialdehyde (MDA) whlch is considered to be an index of serum lipoperoxide was markedly elevated in the diabetic patients.
After 24 weeks of oral administration of 600mg tocopheryl nicotinate (TN), serum MDA decreased significantly. Although serum cholesterol and triglyceride concentrations were not influeced by TN administration, serum cholesterol in the patients with hypercholesterolaemia was significantly reduced. Serum LDL decreased at the late stage of the treatment. Above all, LDL concentrations at a high level were reduced from the early stage of the treatment. ln the patients with low HDL concentrations, TN treatment promptly elevated the serum lipoprotein levels of the patients and maintained high levels during the treatment. Consequently, serum alpha/beta lipoprotein ratio in the diabetic patients was normalized throughout the TN medication.
About 70 percent of the diabetic patients had impaired liver functions, especially, serum alkaline phosphatase and TN administration improved the abnormality of serum alkaline phosphatase.

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