Concentrations of 25-hydroxyvitamin D (25-OH-D), 24, 25dihydroxyvitamin D [24, 25 (OH)2D], and 1α, 25-dihydroxyvitamin D [1, 25(OH)2D] in bone marrow and serum of patients with leukemia and normal subjects were assayed. There were highly significant correlations between the bone marrow and serum concentrations of the respective vitamin D metabolites. Especially, the concentrations of 25-OH-D and 1, 25 (OH)2D in the bone marrow gave very similar values to those in serum. This is a big advantage in controlling the bone marrow levels of vitamin D metabolites in patients with leukemia, because doctors can calculate the bone marrow levels from the serum levels of the respective vitamin D metabolites without bone marrow aspiration. When 1 ochydroxyvitamin D3 (1α-OH-D3) was administered orally to eight patients with leukemia, clinical conditions were improved in seven patients: four complete remissions (CR), one partial response (PR), and two minor responses (MR) without severe hypercalcemia. The results suggest that the therapy with 1α-OH-D3 is fairly effective for curing human leukemia although it is not dramatic.
Plasma levels of vitamin D-binding protein (DBP) and vitamin D metabolites in patients with decompensated and compensated liver cirrhosis were assayed. Plasma levels of DBP in the decompensated group were significantly lower than those in the compensated group, but both were lower than the normal range. The plasma levels of 25-hydroxyvitamin D (25-OH-D) and 1α, 25-dihydroxyvitamin D [1, 25 (OH)2D] in the compensated group were within the respective normal ranges, whereas both values in the decompensated group were significantly lower than those in the compensated group. Most of 25-OH-D (higher than 96%) was confirmed to be circulated as a bound form with DBP in the plasma of not only the compensated but also the decompensated group. When vitamin D2 was given to the decompensated group, a significant increase of 1, 25 (OH)2D levels in the plasma could not be observed while 25-OH-D levels were increased. On the other hand, the administration of 1α-hydroxyvitamin D3 (1α-OH-D3) to the decompensated group caused a significant increase in the plasma levels of 1, 25 (OH)2D. Therefore, we suggest that the administration of 1α-OH-D3 is useful for the treatment of bone disease induced by liver cirrhosis.
A simple and convenient method using a heparin-Ca precipitation technique, which was devised for determination of serum lipoprotein fractions, was applied to the determination of tocopherol concentrations in individual lipoproteins. Three types of precipitates were prepared from 0.25ml serum samples plus 0.1 ml of 5% heparin by mixing at 37°C for 30 min with 5 ml of 0.054 M CaCl2 only, 0.054 M CaCl2 in 0.6 NaCl, or 0.054 M CaCl2 in 0.92% NaCl. These three precipitates consisted of chylomicron+VLDL (very low-density lipoprotein)+LDL (low density lipoprotein), chylomicron+VLDL, and chylomicron only, respectively. The tocopherol content of individual lipoproteins was calculated from the concentrations of tocopherol in these three precipitates, and the values obtained by using this technique were very close to those by a standard ultracentrifugation method. Thus, this simple method appears to be suitable for rapid tocopherol assay of a large number of samples.
The relation of lipoprotein tocopherol levels to red blood cell (RBC) tocopherol was investigated in 81 healthy children, comprising 44 males and 37 females, using a new technique for separation of individual lipoprotein fractions. 1. In children there were no age and sex differences in tocopherol contents among individual lipoprotein fractions. The tocopherol content of high density lipoprotein (HDL) was slightly higher than that of low density lipoprotein (LDL), but this difference was not statistically significant. 2. The tocopherol content of HDL fractions was closely correlated with RBC tocopherol concentration, but there was no relationship in tocopherol levels between RBC and LDL and between RBC and very low density lipoprotein (VLDL). 3. There were no age and sex differences in contents of total cholesterol (T-ch), triglycerides (TG), phospholipids (PL), total lipids, HDL-cholesterol, LDL or VLDL in children.
Changes in the concentrations of vitamin D and its metabolites in plasma of healthy subjects orally given physiological doses of vitamin D2 by multivitamin or vitamin D liquid preparations were determined and the bioavailability of vitamin D was studied. Separative assay on the D2 and D3 compounds of vitamin D, 25-hydroxyvitamin D (25-OH-D), 24R, 25-dihydroxyvitamin D [24, 25(OH)2D], and 1 α, 25-dihydroxyvitamin D [1, 25(OH)2D] was performed in plasma of eight healthy male volunteers. When the concentrations of vitamin D and its metabolites in plasma of volunteers were assayed after daily oral administration of 400 IU of vitamin D2 in a form of multivitamin tablet for 1 week, the variations of vitamin D3 and its metabolites in plasma levels were very small. In contrast, the concentrations of 25-OH-D2 and 1, 25(OH)2D2 slightly increased after the administration, while neither vitamin D2 nor 24, 25(OH)2D2 was detected. A single dose of 4, 000 IU of vitamin D2 was orally given to the volunteers in a form of a vitamin D liquid preparation and the hourly variations were observed during 24 h. These concentrations of vitamin D2, 25-OH-D2, and 1, 25(OH)2D2 were slightly higher than those of the repeated doses. The result suggests that even the high dose of 4, 000 IU has little effect on the plasma levels of vitamin D2 and its metabolites by a single dose, indicating a low risk for hypervitaminosis D.
To demonstrate different effects of bile and Na taurocholate on calcium absorption, in vivo studies and in situ intestinal loop experiments were performed in intact rats. Only bile (collected from donor rats), but not 15 mM Na taurocholate, significantly increased the jejunal mucosa calcium and 45Ca contents after an intragastric administration of test solution containing 7.5 mM CaCl2+45Ca. However, plasma radioactivity which represented lumen to plasma calcium transport was increased by Na taurocholate but not bile, suggesting that both agents enhanced calcium transport across the brush border membrane but in the presence of bile some calcium remained in the mucosal cells. Results from the in situ studies supported the above findings. It was shown that bile and Na taurocholate enhanced the calcium transport from the lumen. However, net absorption was unchanged due to concurrent increase in the efflux of calcium.
A complete diet containing 23% protein was fed to two-dayfasted rats. The effects of this diet on protein biosynthesis, through the examination of liver slices, was investigated. (1) Refeeding enhanced the protein-synthesizing activity with better preservation of heavy polysomes in the liver slices. Protein in the diet was necessary to induce, through refeeding, the activation of protein synthesis in the liver. (2) The incorporation of [3H]methionine into 40S subunits and 80S subunits, where “run-off” 40S and 60S subunits had been accumulated by preincubation with 2×10-6 M pactamycin, was much higher in the liver slices of refed rats than in the liver slices of fasted rats. By using chain initiation inhibitors, it was shown that labeled 40S and 80S subunits were 40S and 80S initiation complexes, respectively.
To investigate the influence of cholesterol content in tissue on the distribution, metabolism, and accumulation of pentachlorobenzene (PECB), rats were fed on a cholesterol-enriched (CHE) diet or a basal diet for 4 weeks. At two weeks, a single dose or a 6-day dosage of PECB was orally administered. The serum cholesterol concentration in the CHE diet group was 2.1-2.9 times higher than that in the basal diet group, while the serum triglyceride concentration decreased. The serum lipid levels were similar to the levels at two weeks. The blood PECB concentration was not different between the two groups. Increases in the contents of PECB and lipid in tissue due to the CHE diet feeding were observed only in liver (PECB, 2.6-3.0 times; triglyceride, 2-3 times; cholesterol, 10-15 times). Content of pentachlorophenol, a main metabolite of PECB, and the level of drug-metabolizing enzymes in liver of the CHE diet group tended to be higher than those of the basal diet group. These results suggested that the increase in PECB accumulation in the liver of the CHE diet group was not due to the decrease of PECB metabolism but due to the increase in the content of cholesterol and triglyceride.
The effects of dietary pantethine levels on the drugmetabolizing system were investigated under administration of varying amounts of autoxidized linoleate (AL) with rat liver microsomes and S-9 fractions. AL having 800meq/kg of peroxide value and 1, 700meq/kg of carbonyl value was dosed to the rats of each group given drinking water containing 0mg% (deficient), 6.25mg% (normal), and 125mg% pantethine (sufficient). The contents and activities of the enzymes in the drugmetabolizing system in the rat liver of each pantethine-level group changed essentially in a similar manner, that is, they were induced at an AL daily dose of 0.2ml/100g body weight (i.e., small dose) for 5 successive days and lowered at a daily dose of 0.4ml/100g body weight (i.e., large dose) by the same administration period, compared with respective nonAL groups in each of the three pantethine levels. In both non-AL and the small-dose AL, enzyme activities of the electron transfer system in rat liver microsomes, aminopyrin-N-demethylase activity, and metabolic activation of 2-acetylaminofluorene in S-9 fractions were significantly higher in the pantethine-deficient group than in the pantethine-normal and sufficient groups. In the large-dose AL, the enzyme activities in the drugmetabolizing system decreased significantly in any pantethine levels, though the survival rate of the rats was higher in the pantethine-sufficient group than in the pantethine-normal groups. The results suggest that the pantethine relieves the effect of dosed AL on the drug-metabolizing system in rat liver.
Wistar rats were submitted to the action of active lectins from common dry beans (Phaseolus vulgaris) and from jack beans (Canavalia ensiformis, DC). Raw common bean was offered to the rats in an otherwise balanced diet to make 10% protein as the sole protein source. A single dose of 20 mg of jack bean lectin (concanavalin A) was given by gastric intubation. Half of the rats receiving raw bean died within 22 days of experiment. Histological findings showed ulceration and necrosis of the intestinal villi in the surviving rats. In some cases the lesions reached also the submucosa. Gastric intubation of concanavalin A caused intense scaling off in the apical portion of the villi.
The effects of the supplementation of methionine (Met), cystine (Cys), and glycine (Gly) to soybean protein or casein on serum and liver lipid levels were studied in rats. Rats were fed cholesterol-free diets containing 25% soybean protein or casein supplemented with 0.75% Met, 2.5% Gly, or a combination of these two for 4 weeks. The addition of Met to soybean protein caused a significant increase in serum cholesterol and this was slightly ameliorated when Gly was given simultaneously. In rats fed casein diets, serum cholesterol tended to decrease when Gly, or Met and Gly were added. A simultaneous supplementation of Met and Gly to casein resulted in a reduction of hepatic cholesterol. Cystine added at the 0.6% level did not cause demonstrable changes in lipid concentrations except for a drop in serum triglyceride of the casein group. When 2.0 Gly was added to cholesterol-enriched diets containing 20% protein, serum cholesterol decreased significantly only when the protein source was casein and the level attained was comparable to that observed in rats fed soybean protein. Liver cholesterol was also markedly decreased by the addition of Gly to casein. The results suggest a possible role of Gly in the regulation of serum cholesterol levels by dietary protein.
The effects of supplementation of methionine to a 20% soy protein isolate diet on serum level of cholesterol, 3-hydroxy-3methylglutaryl coenzyme A (HMG-CoA) reductase activity, cholesterol 7α-hydroxylase activity, and biliary and fecal steroids in rats with or without receiving polychlorinated biphenyls (PCB) were investigated. Supplementation of methionine and PCB did not affect the growth. Serum level of cholesterol was higher in rats fed PCB than in controls. In rats fed PCB, addition of methionine elevated serum level of cholesterol synergistically. The activity of HMG-CoA reductase was higher in rats fed the methionine-supplemented diet than in those fed the unsupplemented diet when PCB was included in the diets. Cholesterol 7a-hydroxylase activity (nmol/h 100g body weight) was higher in rats fed PCB than in controls. Biliary secretion of bile acids was higher in rats fed PCB than in controls. On the other hand, fecal excretion of bile acids decreased in PCB-treated rats, but total steroids were not affected by PCB. In rats fed PCB, the addition of methionine did not alter cholesterol 7α-hydroxylase activity and biliary and fecal steroid output. The data suggest that the increase in serum level of cholesterol due to dietary addition of methionine together with PCB would be mediated through the stimulation of hepatic synthesis of cholesterol.
The effect of age on eicosapentaenoic acid (20:5 n-3; EPA) incorporation into plasma lipids was investigated in young volunteers (8 males, 19±1 yr) and middle-aged volunteers (6 males, 53±7 yr). They were asked to take 5.4g fish oil per day for one week. The increment in EPA in the cholesteryl ester fraction after the supplementation was significantly greater in the middle-aged group (d=1.69%) than in the young group (d=0.44%) (p<0.05). The food intake analyzed for 3 consecutive days just before the supplementation revealed that the young group took more linoleate (17 vs. 10g) than the middle-aged group. There was a significant inverse correlation between the increment in EPA in the cholesteryl ester fraction after the supplementation and daily linoleate intake among all the volunteers combined (γ=-0.63, p<0.02). The higher increment in EPA in cholesteryl ester in the middle-aged group might be due to less intake of linoleate and not due to the difference in age itself.
The influence of sitosterol and sitostanol on the solubility of cholesterol in mixed bile salt micelles in vitro and in vivo was investigated to examine the mechanism by which sitostanol inhibits cholesterol absorption more than does sitosterol. Both sitosterol and sitostanol decreased micellar solubility of cholesterol to a similar extent, when determined with the turbidity. Also, these sterols reduced the concentration of cholesterol in micelles, both in vitro and in vivo. The extent of the reduction of micellar solubility of cholesterol by these sterols was almost the same in vitro, whereas sitostanol tended to reduce the solubility more effectively than sitosterol in vivo. Thus, the interference with cholesterol solubilization in vivo may be responsible for effective inhibition of cholesterol absorption by sitostanol. Since the effect of sitostanol was not observed in vitro, there is a possibility that another factor(s) not included in the in vitro system might affect the action of sitostanol on micellar solubility of cholesterol in vivo.
A long-term experiment was carried out to study the effects of alterations in energy intake and meal contents on basal metabolic rate (BMR) of a normal woman. Alterations of energy intake induced changes in BMR and pulse rate in addition to body weight changes. Whether BMR was expressed per whole body, per unit body weight, or per unit body surface area, it increased progressively during long-term overeating periods, and decreased markedly during long-term undereating periods. These results suggest that there exists `Luxuskonsumption', or adaptive diet-induced thermogenesis, during an overeating period and hypometabolism during an undereating period. BMR was affected significantly by the menstrual cycle but not by nutrient composition when daily energy intake was fixed at 2000 kcal for a long time.