As a chemiluminescence probe, 2-methyl-6-phenyl-3, 7dihy-droimidazo[1, 2-a]pyrazin-3-one was used to detect superoxide anion generation in granulocytes during phagocytosis. The reaction of this probe is highly specific for and sensitive to superoxide anions and can be adopted to determine them in terms of xanthine oxidase units. Generation of superoxide anions in response to opsonized zymosan was checked for granulocytes of peripheral blood samples from 9 adults and those of cord blood samples from 11 neonates. The ability to generate superoxide anions during phagocytosis was found to be greater in granulocytes of cord blood from neonates than in those of peripheral blood from adults.
A novel enzymatic method for the determination of calcium ion (Ca2+) is described. The principle of the assay is to determine the degree of activation by Ca2+ present in a given solution of a Ca2+-dependent enzyme, phospholipase D, which is subsequently assessed in terms of the amount of choline produced. For the latter determination, choline oxidase and peroxidase are used in combination, leading to the color production, which can be simply quantified by measuring the increase in absorbance at 500nm with time. The present method is highly Ca2+-specific, accurate, and reproducible, giving results in reasonably good agreement with those obtained by the Ca2+-selective electrode method. The results of the enzymatic method are not influenced by any change in pH of the serum samples that may occur during the storage of these samples.
Duodenal alkaline phosphatase activities were measured in rats treated with cysteamine, a drug which causes duodenal ulcers in experimental animals. In the proximal duodenum, a significant decrease in alkaline phosphatase was observed 24h after cysteamine injection. The inhibitory effect seems site-specific, since the enzyme in the upper jejunum remained unchanged. Moreover, the effect of cysteamine is apparently alkaline phosphatase-specific, because duodenal acid phosphatase, leucine aminopeptidase, and bicarbonate-dependent ATPase did not show any significant change in activity. A mechanism of the inhibitory effect of cysteamine on alkaline phosphatase is discussed.
The effects of prostaglandin (PG)I2 and (E)-3-[4-(1-imidazol-methyl)phenyl]-2-propenoic acid hydrochloride monohydrate (OKY-046), a thromboxane A2 synthetase inhibitor, on endotoxin-induced experimental disseminated intravascular coagulation (DIC) were studied in rats. Experimental DIC was induced by a 4h sustained infusion of endotoxin at a dose of 100mg/kg of body weight. Rats were infused continuously with PGI2 at 2.4×10-7-1.2×10-4g/kg or with OKY-046 at 2.4×10-8-2.4×10-4g/kg into a femoral vein for 4h. Simultaneously with the agent infusion, endotoxin (100mg/kg/4h) was administered into the contralateral femoral vein. A protective effect against DIC was noted in the rats treated with 2.4×10-5 or 1.2×10-4g/kg of PGI2, or with 2.4×10-8-2.4×10-4g/kg of OKY-046 with respect to the following parameters: fibrinogen and fibrin degradation products, fibrinogen level, prothrombin time, partial thromboplastin time, platelet count, and the number of renal glomeruli with fibrin thrombi. These results demonstrated that PGI2 or OKY-046 reduces the extent of changes of the coagulation parameters caused by DIC.
The effects of fasting and refeeding on the adaptive changes in intestinal sugar absorption was observed by measuring the transmural potential difference (ΔPD) evoked by glucose by infusion of sugars and compared with those in disaccharidase activities, glucose uptake and phlorizin binding activity to the brush border membranes, and morphological parameters. Rats were fasted for 1, 3, or 5 days. The rats fasted for 5 days were refed for 1 or 3 days further. The ΔPD evoked by glucose, maltose, or sucrose in everted jejunal segments decreased within 1 day of fasting, remained at a same level during fasting, and then increased to the control level after refeeding. Maltase and sucrase activities did not change during the first day of fasting, but did so significantly after 3 days of fasting, in terms of both specific and total activities. On refeeding, disaccharidase activities increased rapidly. However, in spite of significant changes in ΔPDs and disaccharidase activities, glucose uptake by and phlorizin-binding to brush border membrane vesicles from jejunal mucosa did not change in either 5 day-fasted or refed animals compared with the control group. On the other hand, jejunal villus height in rats fasted for 5 days decreased significantly compared with that in control rats and was accompanied by a reduction in epithelial cell height and surface area of villi. These results suggest that the absorption of sugar in small intestine could adapt to fasting and refeeding with changes in disaccharidase activity and surface area, without any change in glucose carrier.
This study was designed to investigate the effects of synthetic estrogen on the metabolism of ascorbic acid in adult female guinea pigs. The animals were maintained on an ascorbic acid-free diet ad libitum. Oral administration of estrogen (estinyl, 5μg) in combination with 5mg of ascorbic acid daily for 21 days resulted in a significant decrease in plasma, liver, adrenal, and urinary concentrations of ascorbic acid, compared with those of the animals receiving only 5mg of the vitamin. Using [14C]ascorbic acid, the rate of exhalation of CO2 appeared to be markedly higher in animals receiving ascorbic acid alone than in animals given the vitamin simultaneously with estrogen. The bioavailability of ascorbic acid during the first 300min was reduced by 25% following concomitant administration of estrogen. Furthermore, in animals receiving ascorbic acid plus estrogen, fecal levels of the vitamin were significantly higher than the controls receiving ascorbic acid alone. These observations indicate that estrogen-associated decreased levels of ascorbic acid in plasma, tissues, and urine may be due to impairment of the gastrointestinal absorption of the vitamin.
Skin collagen samples from vitamin B2- or B6-deficient rats, weight-matched controls, and control rats fed ad libitum were examined for biomechanical and biophysical properties like tensile strength, shrinkage temperature, gel-reversibility of salt-soluble collagen, and susceptibility of insoluble collagen to denaturing and proteolytic agents. Deficiencies of riboflavin and pyridoxine, as well as food restriction, significantly reduced the tensile strength and shrinkage temperature and increased the gel-reversibility of collagen. The changes tended to be of greater magnitude in collagen from the vitamin-deficient rats. Solubilization of insoluble collagen by denaturing and proteolytic agents was markedly increased in collagen from riboflavin- or pyridoxine-deficient animals but not in that from food-restricted rats. The results of this study support the hypothesis that the skin changes seen in riboflavin and pyridoxine deficiencies may be due to impaired collagen cross-linking and consequent alterations in the physical properties of the skin.
We tested the effect of bestatin [(2S, 3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-leucine] on the serum levels of various hydrolytic enzymes in a patient with progressive muscular dystrophy. Long-term administration of bestatin significantly suppressed the serum levels of aspartate aminopeptidase, arginine aminopeptidase, carboxypeptidase, alkaline phosphatase, and esterase. The results of multivariate study performed on the enzyme networks are compatible with the notion that this drug has a synchronizing effect on the movements of enzyme networks. Although in this middle-aged patient with an established disease the levels of enzymes of muscular origin were not significantly suppressed by this treatment, the present findings may warrant a therapeutic trial with this agent on young patients with initial symptoms of the disease.
The normal levels of apolipoproteins in Japanese were investigated by the single radial immunodiffusion method. No differences were seen between the males and females in the apolipoprotein A-I, B, and C-III levels. However, the levels of apolipoproteins A-II and C-II were higher in the males, while that of apolipoprotein E was higher in the females. These differences were statistically significant. Except for apolipoprotein E, the apolipoprotein levels tended to increase with age more in the females than in the males. The apolipoprotein E level showed a statistically significant positive correlation not only with the total cholesterol level but also with the high density lipoprotein-cholesterol level.
Nutritional status in patients with liver cirrhosis was evaluated with the use of anthropometric, visceral protein, and immunological parameters, with special reference to plasma amino acid imbalance. By cluster analysis using 7 nutritional parameters, we identified 10 groups (clusters). Most of the patients with decompensated liver cirrhosis (82.3%) were distributed into Clusters VIII, IX, and X, exhibiting a marked decrease in visceral protein status with or without reduced anthropometric parameters (i.e., kwashiorkor-like syndrome). In addition, the reduction in visceral protein status (serum albumin, transferrin, prealbumin, and retinol-binding protein) was highly correlated with plasma amino acid imbalance, i.e., the decrease in the molar ratio of branched-chain amino acids (BCAA) to aromatic amino acids (Fischer's ratio). Moreover, the plasma clearance rate of BCAA, but not that of other essential and nonessential amino acids, was found to be significantly increased in cirrhotic patients, suggesting that the decrease in plasma BCAA is due mainly to augmented utilization of these amino acids by the peripheral tissues (i.e., skeletal muscle, etc.). These findings support the view that nutritional therapy with BCAA supplementation is of practical importance for clinical improvement of the protein malnutrition often observed in patients with liver cirrhosis.