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Physiological strain plays an important role in maintaining the normal function and metabolism of bone cells. It is well known that the mineral content of astronauts' bones decreases during spaceflight. Thus, gravity is one of the important factors in the muscloskeletal system. The vector-free horizontal clinostat has been used to simulate conditions of microgravity for examining such effects on cells in culture. We analyzed the effects of simulated microgravity using a horizontal clinostat on cultured osteoblast-like cells (HuO9 cell line). Total cellular protein, which was measured as an indication of cell proliferation, was not significantly inhibited under simulated microgravity conditions. No morphological changes were detected under microgravity conditions by phase-contrast microscopy. However, the alkaline phosphatase (ALP) activity and osteocalcin production of the HuO9 cells decreased significantly under microgravity conditions. Our data indicate that simulated microgravity directly inhibits some differentiation phenotypes and some functions of osteoblasts. On the other hand, the addition of 1,25-dihydroxy-vitamin D₃ (1,25-(OH)₂-D₃) increased ALP activity under simulated microgravity conditions, although the total activity of ALP in the cells treated with 1,25-(OH)₂-D₃ was still lower under simulated microgravity conditions than that in the control cells. However, the cells under simulated microgravity conditions showed a greater enhancement of ALP activity by treatment with 1,25-(OH)₂-D₃.

Our aim was to study the effect of iron supplementation on the following aspects of erythrocyte metabolism in experimental hyperthyroidism: glutathione (GSH) levels, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities. Hyperthyroidism induced by L-thyroxine administrations significantly raised erythrocyte GSH, GSH-Px and SOD levels of the rats (P < 0.001). Likewise, we observed that iron supplementation induced significant rises in erythrocyte GSH, GSH-Px and SOD levels (P < 0.001) as compared with the control group. The erythrocyte GSH, GSH-Px and SOD levels of hyperthyroidism-induced iron-supplemented animals were significantly higher when compared with either the iron-supplemented group (P < 0.001) or the only L-thyroxine-administered hyperthyroid group (P < 0.001, P < 0.05, P < 0.01, respectively). The results of this study show that L-thyroxine administration and/or iron supplementation increases GSH, GSH-Px and SOD levels of erythrocytes.

A study was conducted to examine the relationship of testicular atrophy to bone metabolism in male leprosy patients. The study consisted of 31 leprosy patients (mean age: 62.0 years) and 31 healthy control men (mean age: 60.0 years). Measurements were made of their serum levels of free testosterone (FT), estradiol (E₂), luteinizing hormone (LH) and 25-hydroxyvitamin D (25 OHD). Bone mineral density (BMD) was measured at radial sites and the lumbar vertebral bodies (L2-L4) by dual-energy X-ray absorptiometry using a Hologic QDR-2000 densitometer. FT and E₂ levels were significantly lower and LH levels higher in leprosy patients than in controls. This represents a primary hypogonadal pattern. A value of 7.20pg/ml of FT (= Mean -1 SD of control) was used as a cut off value, and the subjects were subdivided into a hypogonadal group (HG) and a non hypogonadal group (non-HG). When the subjects were compared for differences in age, age at onset of disease, duration of disease, body mass index and BMD, only the duration of disease and BMD were significantly different between the two groups. Furthermore, BMD of the forearm significantly correlated with FT levels (r = 0.689, P < 0.0001). Low BMD may be due to orchitis and testicular atrophy.

To clarify the nature of nitrogen metabolism between branched chain amino acid (BCAA) and glutamine (GIn) in liver failure, we measured arterial plasma concentrations of GIn and ¹⁵N uptake to amino-N and amide-N of GIn in normal and D-galactosamine-induced fulminant hepatic failure (FHF) rats after ¹⁵N-leucine (Leu) injection. Fifteen, 30 and 60 min after Leu injection, the arterial plasma concentrations of GIn were significantly higher in FHF rats than in controls. The concentrations of amino-¹⁵N GIn were also significantly higher in FHF rats than in controls at 5, 15, 30 and 60 min after injection. The concentrations of amide-¹⁵N GIn did not significantly differ between FHF and controls at 5, 15 and 30 min. However, at 60 min, the concentration was significantly higher in the FHF rats. The higher uptake of ¹⁵N to amino-N of GIn in FHF rats suggests the presence of an enhanced ability to synthesize GIn from Leu in FHF rats. The higher uptake of ¹⁵N to amide-N of GIn in FHF rats at 60 min after injection suggests that excessive administration of BCAA to patients with severely impaired urea-cycle capacity suffering with hepatic failure may lead to greater levels of hyperammonemia.

Plasma 5-hydroxytryptamine (serotonin), tryptophan, neopterin and cortisol levels were measured in patients with depressive cancer cachexia and in healthy controls during the same time period. Patients with advanced cancers had significantly raised neopterin, a marker of endogenous gamma-interferon (IFN-γ) production, and cortisol values, but decreased serotonin and tryptophan levels. Much work has been done to elucidate the possible role of serotonin in depressive states. IFN-γ induces a high level of indoleamine dioxygenase (IDO), a tryptophan degrading enzyme, and high cortisol levels induce high tryptophan oxygenase activity, which in turn increases metabolism along the tryptophannicotinic acid pathway. These results suggest that persistent immune activation and intense adrenal activity occur in patients with cancer cachexia, resulting in disorders involving tryptophan metabolism followed by depression in cancer cahexia.

To evaluate worker's exposure to mixed solvents, equations for the calculation of the biological hazard index, which is defined as biological levels tolerable for exposure to mixture, were developed. When biological levels of exposure indicators were not affected by coexposure, rules similar to those for airborne monitoring could be applied. Namely, when the components had additive effects, the biological hazard index was calculated from the concentration of urinary metabolites or parent solvents, by an equation which was essentially similar to the equation for the calculation of the hazard index. In the present study, the confidence limits of the biological hazard index and predictive limits for individual specimens were calculated. These equations could be used under the condition that the uptake, metabolism and elimination of solvents were practically unaffected by coexposure. When urinary metabolites or solvents of some components of a mixed solvent alone were determined and those of the remaining components were not determined, the concentration of urinary metabolites or solvents of remaining components were estimated from the airborne concentration of the other components.

This study assessed total and segmental distribution of fat mass (FM) in athletes with spinal cord injury (SCI) and examined the relationships between segmental distribution of fat mass and age, injury level, athletic history, and training load in order to provide useful information for improvements in their physical strength and training. Twenty-five male athletes with SCI participated in the study. The whole bone composition was measured by a dual-energy X-ray absorptiometry (DXA) method for the calculation of bone minerals, FM, and fat-free mass. The percent fat of the trunk, arms, and legs was also calculated. The percent fat in the legs was highest in comparison with that in the trunk and arms (p < 0.001), and the percent fat in the trunk was higher than that in the arms (p < 0.001). The body fat (p < 0.01), waist circumference (p < 0.01), and waist-to-hip ratio (p < 0.0001) were higher in the group aged 40 or older in comparison with that aged 39 or younger. Path analysis revealed that training load was a factor decreasing the percent fat on the arms and trunk (p < 0.01), and athletic history was a factor reducing the percent fat on the arms (p < 0.05). Our study suggests that exercise is effective in reducing the waist circumference, waist-to-hip ratio, and percent body fat of SCI individuals, and that such effects can help to enhance athletic performance and likely to protect against development of metabolic syndromes resulting from a sedentary lifestyle.

Pharmacokinetic analysis of the distribution and concentration of adriamycin (ADM) in mouse plasma and tissues was carried out by differentiating the unmetabolized form from metabolized ones using high-performance liquid chromatography after a single intravenous injection. Marked differences between ADM and total ADM equivalent values (total ADM values) or its metabolized forms were observed in the pharmacokinetic behavior in plasma and tissue distributions. The ratios of tissue per plasma for total ADM and for ADM values in the liver, kidney and heart showed a two-digit magnitude each time they were examined. Twenty four h later, the ratios for ADM values in the liver, kidney, heart and lung were at high levels; 43.1, 48.1, 57.9 and 45.5 times, respectively. Twenty min after injection the ratios for total ADM values in the spleen, lung and tumors were comparatively small, but 24 h later, the ratio had increased 36.5, 45.5 and 6.8 times respectively.

The applicability and accuracy of isotachophoresis in measuring the concentrations of some of the intermediates of red cell metabolism during blood bank storage in acid-citrate-dextrose preservative was assessed. Preparative treatment consisted of washing with isotonic sucrose solution and centrifugation to remove serum, but white cells and platelets were not separated out from red blood cells. The results for 2,3-diphosphoglycerate, ATP, inorganic phosphate and lactate were also confirmed enzymatically. The technique had good reproducibility (variation less than 3%) and was extremely convenient compared to traditional enzyme assays of the same components. It enabled simultaneous measurement of components with concentrations greater than 1 mumole/red blood cell.

The sensitivity of five kinds of cytotoxicity assays using ethanol on human hepatoblastoma cells (HUH-6 line), which were cultured as monolayers or spheroids, was compared. Ethanol was chosen as a test because it acts on cell membranes directly without being metabolized and exerts its cytotoxicity. The assay methods used were as follows: 3- (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), colony formation, cell growth and DNA assays. The sensitivity of the assays was: LDH < DNA < cell growth < MTT < colony formation. LDH assay had the advantage that the same culture could be used for multiple assays, but when a small number of cells were assayed, no significant increase in the release of LDH was detected in the assay cultures compared with the control cultures. Although the DNA and cell growth assays were more sensitive than the LDH assay, the extent of cell damage may be underestimated because the damaged cells and DNA present in the cultures are included in the assay samples. On the other hand, both MTT and colony formation assays showed a high sensitivity. The MTT assay was done within 24 h after ethanol was added to the cultures and was applicable to both monolayer and spheroid cultures, while the colony formation assay required 1-2 weeks and it was applicable only to monolayer cultures. Taken together, the MTT assay was the most suitable method to evaluate the cytotoxic effects of ethanol on HUH-6 cells cultured as either monolayers or spheroids.

This study was undertaken to assess postoperative gastric motility and gastric acid secretion, and pre- and postoperative carbohydrate metabolism in patients with esophageal cancer. The gastric motility was compared among 3 different reconstruction routes in 26 patients who were divided into 2 groups according to the duration of postoperative follow-up; group A, 3 months or less; and group B, 18 months or more. The routes used for subtotal resection of the stomach were the posterior mediastinal, retrosternal, and subcutaneous routes. All patients showed positive resting pressure in the esophagus, but peristaltic waves did not reach the gastric tube at dry swallowing in any patients and peristaltic waves appeared after eating pudding only in 1 patient in group B. The resting pressure and gastric emptying time were similar among reconstruction routes, but the incidence and amplitude of metoclopramide (MCP)-induced peristaltic waves were significantly higher in group B than in group A. Furthermore, 24-h intragastric pH monitoring of gastric secretion in a group of 9 patients revealed individual variation in gastric secretion. Some patients showed high acidity soon after operation, suggesting the need for prophylactic treatment for preventing gastric ulcer. Postoperatively, postprandial serum gastrin levels were significantly higher than preoperative levels. In the other group of 11 patients tested, preoperative and postoperative carbohydrate metabolism were not significantly different. Postoperatively, carbohydrate metabolism recovered to preoperative levels after a transient decrease. These results demonstrated that postoperative motility improved over time although no difference was found among the 3 reconstruction routes used.

We observed differences in the capillary architecture of the skeletal muscles that have different fiber metabolism. The soleus, the vastus intermedius and the tibialis anterior muscles of adult Wistar rats were prepared using two different techniques. Samples for adenosine triphosphatase (ATPase) staining were prepared following Dubovitz's method, and the distributions of fiber type, Types 1, 2A and 2B, were analyzed. Then, corrosion casts of capillary architecture of these muscles prepared following Murakami's method were observed with a scanning electron microscope (SEM) and compared with the fiber distribution. The fiber type composition of the soleus muscle showed Type 1 (slow-twitch) dominance and that of the vastus intermedius and the tibialis anterior muscle showed Type 2 (fast-twitch) dominance. The capillaries of the soleus muscle were tortuous, and this was thought to be advantageous for blood supply. In contrast, the capillaries of the vastus intermedius and tibialis anterior muscles had a relatively parallel pattern. Additionally, two different patterns of capillary architecture that appeared to correspond to certain metabolic characteristic of different muscle fiber types were preserved with corrosion casting. In conclusion, comparative studies on capillary architecture of the skeletal muscles are useful for analyses of its function.

The plasma level of isosorbide dinitrate intraperitoneally administered to rats stressed by foot-shock was almost the same as that in non-stressed control rats. However, levels of its metabolites, 5-isosorbide mononitrate and 2-isosorbide mononitrate, were lower in stressed rats than in non-stressed rats, suggesting that stress may influence the metabolism and/or excretion of the metabolites.

We studied the brains of two cases of amyotrophic lateral sclerosis with dementia. Bunina bodies were found in the motor neurons of cranial nerve nuclei (trigeminal, facial and hypoglossal nerves) as well as in the spinal motoneurons. They appeared mostly in the cytoplasm and occasionally in the neuronal processes. However, the present electron microscopic study disclosed clearly that Bunina bodies were present not only in the cell body but also in the dendrites. No Bunina bodies were observed in the axons. It is inferred that the Bunina bodies were degenerative products formed as a result of a protein metabolism disorder.

The excretion of 3-mercaptolactate-cysteine mixed disulfide [S-(2-hydroxy-2-carboxyethylthio)-L-cysteine, HCETC], sulfate and taurine in the urine of normal adults was investigated before and after oral administration of L-cysteine and related sulfur-containing amino acids. Before the loading of amino acids, the excretion (mean +/- SD) per kg of body weight per day of HCETC, free sulfate and taurine was 0.096 +/- 0.042, 305.7 +/- 66.1 and 31.9 +/- 8.7 mumols, respectively. After the loading of L-cysteine (800 mumols/kg of body weight), the average excretion in the 24-h urine of HCETC increased 2-fold and that of taurine increased 1.6-fold. The average excretion of free sulfate after the L-cysteine loading was 989.4 +/- 145.1 and 388.8 +/- 51.6 mumols/kg per day in the first and second 24-h urine, respectively, indicating that the sulfur corresponding to 85% of the L-cysteine loaded was excreted as free sulfate in 24 h. Administration of L-cystine (400 mumols/kg) resulted in similar results. The increase in HCETC after L-cysteine or L-cystine administration indicates that L-cysteine is metabolized in part through the transamination pathway (3-mercaptopyruvate pathway) and that an equilibrium exists between the intake and excretion of sulfur in humans.

<p>Tissue contents and urinary excretion of taurine were studied in rats after the administration of L-cysteine and its derivatives. Average taurine content in the liver of rats fed a 25% casein diet for 7 days increased 2-fold 2h after the intraperitoneal administration of 5 mmol of L-cysteine per kg of body weight, whereas that in rats fed a 5% casein diet for 2 days increased only slightly. The difference in the liver taurine contents between these two groups was discussed in relation to cysteine dioxygenase. Taurine contents in the heart, brain and blood did not differ significantly between these two groups or between the control and the group of rats which received L-cysteine. The increase in liver taurine concentrations after L-cysteine administration was much higher than that after L-cystine administration, suggesting a difference in their absorption. The intraperitoneal administration of 5 mmol/kg of L-2-oxothiazolidine-4-carboxylate (OTCA) resulted in a 3-fold increase in liver taurine content. The average increase in taurine excretion in the 24-h urine after OTCA administration corresponded to about 6.0% and that in the next 24-h urine to about 2.6% of OTCA administered, suggesting that nearly 10% of OTCA was metabolized to taurine and excreted in the urine.</p>

Formation of sulfate in rat liver mitochondria was studied. About 0.1 mumol of sulfate was formed in mitochondria from 1 g of liver in 60 min when 10 mM L-cysteine was used as the substrate. Addition of either 10 mM 2-oxoglutarate or 10 mM glutathione to this system increased sulfate formation 3 to 4 times. The addition of both 2-oxoglutarate and glutathione resulted in a 20-fold increase in sulfate formation. Sulfate formation in the presence of 5 mM L-cysteine was 58% of that with 10 mM L-cysteine. L-Cysteine-glutathione mixed disulfide was not a good substrate, indicating that this mixed disulfide was not an intermediate of sulfate formation in the present system. Incubation of 3-mercaptopyruvate with rat liver mitochondria also resulted in sulfate formation, and the addition of glutathione accelerated it. Formation of sulfite and thiosulfate was also detected. These results indicate that sulfate is produced in mitochondria, at least in part, from L-cysteine through the transamination pathway (3-mercaptopyruvate pathway).

The purpose of this study was to evaluate the role of arachidonic acid metabolites in the reimplantation response after lung transplantation in mongrel dogs. The left lung was used and two groups were studied. Group I underwent hilar stripping, while Group II underwent hilar stripping plus warm ischemia for 60 min., achieved by clamping the left pulmonary artery and veins. We measured the lung wet to dry weight ratio (W/D ratio), total pulmonary vascular resistance (TPVR), and blood and bronchoalveolar lavage fluid (BALF) levels of leukotriene B4 and C4 (LTB4,C4) and thromboxane B2 (TXB2). These parameters were measured periodically for 7 days after reperfusion. In group II, the W/D ratio and TPVR were significantly increased in comparison with Group I. The blood LTC4 level was elevated immediately after reperfusion, and BALF level of LTC4 also rose subsequently. These levels changed concomitantly with the W/D ratio. The above results suggest that arachidonic acid metabolism plays an important role in the reimplantation response, especially in pulmonary edema.

Carbohydrate metabolism of rats with obstructive jaundice caused by bile duct ligation was studied by intravenous glucose tolerance test (IVGTT) and by liver perfusion. The altered levels of carbohydrate-metabolizing enzyme were examined in relation to the glucose metabolism of the cholestatic rats. In the IVGTT, the rate of fractional glucose removal was increased with increases in plasma insulin and glucagon and with a decrease in non-esterified fatty acid. In liver perfusion, neither the glucose uptake nor insulin extraction by the whole liver of icteric rats was different from the control. The increased rate of glucose removal in IVGTT may be due to enhanced glucose utilization by peripheral tissues resulting from hypersecretion of insulin. In liver perfusate supplemented with glucose, a decrease in the glucose uptake per unit liver weight was observed in relation to the lowered glucokinase activity. Formation of glycogen from glucose and of glucose from lactate was also impaired, indicating inhibition of the gluconeogenic system or relative hyperfunction of the glycolytic system, which may further contribute to the reduction in glycogen content. These metabolic disorders correlated well with the changes in activities of key carbohydrate-metabolizing enzymes, which showed a characteristic pattern consistent with the loss of differentiated hepatic functions. Uptake of glucose and its conversion to glycogen were reduced in the cholestatic liver in close association with altered activities of some of related enzymes. However, due to increased utilization by the peripheral tissues, the total amount of glucose utilized in the whole rat was not reduced.