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Biomedical subjects

S Moriuchi

Publications and source records attributed to S Moriuchi.

At least 73 records · Page 4Linked to original sources
PubMed1979

Some characteristics of early appearing isomaltase in intestinal mucosa of suckling rat.

Characteristics of early appearing free isomaltase in the soluble fraction were investigated in rat intestinal mucosa. Soluble isomaltase and membrane-bound sucrase-isomaltase complex were prepared from 15-day-old rat intestine. Immunochemical properties, optimal pH and heat sensitivity of soluble isomaltase were compared with those of membrane-bound isomaltase. Optimal pH of free isomaltase in the soluble fraction was lower than that of membrane-bound isomaltase. Soluble and membrane-bound isomaltase showed different sensitivities for temperature. Furthermore, membrane-bound isomaltase in 15-day-old suckling rat intestine gave a single line with antiserum. However, soluble isomaltase gave no precipitin line. From these results, it could be concluded that soluble isomaltase is not derived from the isomaltase moiety of membrane-bound sucrase-isomaltase complex as a result of mechanical fragility and rather it would be lysosomal in origin.

Animals↗
PubMed1978

Developmental changes in the sucrase-isomaltase complex in rat intestinal mucosa.

Developmental changes in sucaras-isomaltase complex formation were investigated in intestinal mucosal homogenates and brush border membranes of 15-day-old, 18-day-old and adult rats using Sephadex G-200 column chromatography and polyacrylamide disc gel electrophoresis. Disaccharidases were solubilized by papain treatment. The molecular weight of the complex did not change during development, however, the activity ratio of sucrase to isomaltase increased during development. Furthermore, a significant amount of free isomaltase, which was probably not to be derived from intestinal brush border membrane, was detected before the weanling.

Aging↗
PubMed1978

Inhibitory effect of cadmium on vitamin D-stimulated calcium transport in rat duodenum in vitro.

In vitro effect of cadmium on vitamin D-stimulated calcium transport in the rat was studied using the everted gut sac technique. Calcium transport was significantly inhibited by the addition of cadmium to the mucosal incubation medium. Furthermore, the kinetic analysis of inhibitory effect of cadmium on calcium transport revealed that the type of inhibition was competitive. The apparent "Km" and "Vmax" value for calcium was 1.0 mM, and 2.86 mumoles ml-1.hr-1, respectively. An apparent "Ki" for cadmium was 0.02 mM.

Animals↗
PubMed1978

Effect of various sugars on the induction of chick embryonic intestinal disaccharidases in the organ culture system.

Disaccharidases activities in 20-day-old chick embryonic intestine were induced by the addition of sucrose, maltose, fructose and glucose to the culture medium. However, maltitol, which cannot be digested by intestinal enzymes, showed no effect on the induction of disaccharidase activity. Kinetic study of the enzymes demonstrated that the maximum velocity (Vmax) and the Michaelis constant (Km) of sucrose induced disaccharidases activities of the explants showed changes similar to those observed in the chick of same developmental stage in vivo. Namely, Vmax values of sucrase and maltase were increased. Km values of sucrase did not change, but that of maltase showed a significant decrease during development.

Animals↗
PubMed1978

The effect of vitamin D3 and dietary calcium level on the cadmium-induced morphological and biochemical changes in rat intestinal mucosa.

The effect of vitamin D3 and dietary calcium level on the cadmium-induced changes was observed in the duodena of rats raised on various diets differing in vitamin D and calcium levels. Observation with scanning electron microscopy revealed that vitamin D and dietary calcium were required for normal intestinal villi and microvilli formation. The damaged cells were observed in the intestinal villi of cadmium-exposed rats. Furthermore, dietary cadmium reduced the enzyme activities in microvilli. Especially, alkaline phosphatase activity was reduced in the cadmium-exposed groups, even though it was still responsive to vitamin D3. These effects with cadmium were modulated by vitamin D3 and dietary calcium level. That is, in the presence of vitamin D3 and calcium, the effect of cadmium on intestinal villi and microvilli was reduced.

Cadmium↗
PubMed1977

Some characteristics of cytosol binding protein for 1alpha,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol in rat intestinal mucosa.

Cytosol binding protein for 1alpha,25-(OH)2D3 and 25-OHD3 was demonstrated in rat intestinal mucosa using sucrose density gradient ultracentrifugation analysis, Sephadex G-200 column chromatography and polyacrylamide disc gel electrophoresis. The binding protein has a sedimentation constant of 5-6S, a molecular weight of 100,000-120,000 daltons and a mobility in electrophoresis of Rf 0.42. Further analysis of binding behavior by DEAE-cellulose filter assays revealed that the bindig protein had a higher affinity for 25-OHD3 than for 1alpha,25-(OH)2D3, and that 1alpha,25-(OH)2D3 competed with 25-OHD3 for the same binding site on the protein. The apparent dissociation constant for 1alpha,25-(OH)2D3 and 25-OHD3 was 9.2 X 10(-9) M and 1.5 X 10(-9) M, respectively. The binding capacity was 3.1 pmoles/mg protein for both 1alpha,25-(OH)2D3 and 25-OHD3. The order of binding affinity was 25-OHD3 greater than 1alpha,25-(OH)2D3 greater than D3 = 1alpha-OHD3.

Animals↗
PubMed1977

Induction of chick embryonic intestinal disaccharidases by hydrocortisone and sucrose in the organ culture system.

The effect of hydrocortisone and sucrose on the development of chick intestinal disaccharidases was studied using the organ culture system. When intestines of 15- and 17-day-old embryos were cultured in the presence of hydrocortisone, there was significant enhancement of disaccharidases activity compared with the control. However, there was no effect in the 20-day embryonic intestines. On the other hand, the disaccharidase activity of cultured intestines from 20-day-old chick embryos were significantly stimulated by the addition of sucrose. The observed increase in disaccharidase activity induced by the administration of hydrocortisone in 17-day-old embryos in vitro was sensitive to actinomycin D and cycloheximide. The activity induced by the administration of sucrose in 20-day-old embryos in vitro was sensitive to cycloheximide but insensitive to actinomycin D.

Animals↗
PubMed1977

Characterization of sterol carrier protein binding with 7-dehydrocholesterol and vitamin D3.

The interaction of rat liver sterol carrier protein (SCP) and 7-dehydrocholesterol or vitamin D3 was analyzed by the method of Scatchard plots and gel filtration on Sephadex G-100. Scatchard plots of binding data revealed that the binding behavior for 7-dehydrocholesterol was monophasic, while that for vitamin D3 was biphasic. In 7-dehydrocholesterol, the apparent number of binding sites and the apparent assocation constant K were 0.72 nmoles/mg protein and 8.75 X 10-7M-1, respectively. On the other hand, vitamin D3 showed two types of binding sites differing in affinity. The apparent number of binding sites and the K for high affinity binding were 0.65 nmoles/mg protein and 7.08 X 10-7M-1, those for low affinity binding were 1.51 nmoles/mg protein and 0.36 X 10-7M-1, respectively. Gel filtration of SCP on Sephadex G-100 column gave three protein peaks (peaks I, II and III protein according to the elution orders; Ve/Vo=1.0, 1.56 and 2.29, respectively). 7-Dehydrocholesterol was able to bind with peak III protein, while vitamin D3 was bound peaks II and III protein, respectively. The molecular weight of peak II protein was estimated to be 44,000 and that of peak III protein was 16,000. From these results, it was clearly demonstrated that SCP was involved in the transformation of 7-dehydrocholesterol to cholesterol and could also bind vitamin D3.

Animals↗
PubMed1976

Development of 1,25-dihydroxycholecalciferol receptor in the duodenal cytosol of chick embryo.

The development of 1,25-(OH)2D3 receptor in the duodenal cytosol of chick embryo was studied by the sucrose density gradient analysis. The binding profile for 1,25-(OH)2D3 in the cytosol of vitamin D-deficient chick duodenum on the sucrose density gradient revealed 3 binding components, and the sedimentation constant was estimated as 2.5, 3.5 and 5.5S respectively. The 3.5S binding component has high affinity and low capacity for 1,25-(OH)2D3 and is thought to be 1,25-(OH)2D3 receptor. During the development of chick embryo, the 3.5S binding component was not detected in 13-day embryonic duodenum, it appeared on 15th day of incubation and then gradually increased to the level of vitamin D-deficient chick on 19th day of incubation. The 5.5S binding component was specific for 25-OH-D3 and it was found even in 13-day embryo, but it did not show any significant change during development. On the other hand, the 2.5S component was not specific for either 1,25-(OH)2D3 or 25-OH-D3. However, it was main binding component in early stages of development and decreased during development. From these results, it is suggested that the receptor for 1,25-(OH)2D3 is available a few days before hatching and the inability to produce CaBP in the duodenum of chick embryo could not be ascribed to the absence of the receptor.

Animals↗
PubMed1976

The effect of 1alpha-hydroxyvitamin D3 and cortisone on the development of chick duodenal alkaline phosphatase in organ culture.

The development of alkaline phosphatase influenced by 1 alpha-OH-D3 (a synthetic active form of vitamin D3) and cortisone was studied in chick duodenal organ cultures. The administration of cortisone to the embryo in ovo on the 14th day of incubation resulted in a precocious increase in alkaline phosphatase after six days (20-day embryo). When duodena from 14-, 18- and 20-day embryos were cultured in the presence of cortisone, there was no significant enhancement of alkaline phosphatase activity except for a marginal effect observed in the 18-day duodenum. On the other hand, the alkaline phosphatase activity in cultured duodena from 20-day chick embryos was significantly stimulated by the addition of 1 alpha-OH-D3. The effects of cortisone and 1 alpha-OHD-3 were not additive. The activity of maltase, another intestinal enzyme, was not influenced by 1 alpha-OH-D3. Studies on inactivation of alkaline phosphatase by EDTA suggest that the observed increase in alkaline phosphatase activity induced by the administration of 1 alpha-OH-D in vitro may be related to the qualitative changes in the enzyme that take place during development in vivo.

Alkaline Phosphatase↗
PubMed1976

Synthesis and biological activity of 5,6-trans-vitamin D3 in anephric rats.

A modified procedure for the purification of 5,6-trans-D3 from a reaction mixture of vitamin D3 with iodine and its biological activity in sham-operated and anephric rats are described. When a solution of vitamin D3 in n-hexane was reacted with small quantities of iodine under influence of visible light, the reaction mixture gave four or five spots, including vitamin D3 and 5,6-trans-D3, on a thin layer chromatogram. After purifying the mixture by alumina column chromatography, a colorless oil from the separated 5,6-trans-D3 fractions was crystallized from n-hexane and snow white crystalline 5,6-trans-D3 was obtained. The purification method was thought to be better than the previously reported methods (14-16) because it gave good yield without the procedure of esterification using expensive p-phenylazobenzoyl chloride. A dose of 25 mug of 5,6-trans-D3 obtained thus gave significant elevation on intestinal calcium transport in both sham-operated and anephric rats, whereas the dose did not give positive effects on serum calcium levels in anephric rats. Serum phosphorous levels were extremely elevated by nephrectomy, but in both sham-operated and anephric rats they were unaffected by the administration of 25 myg of 5,6-trans-D3.

Animals↗
PubMed1976

Proteins of chick duodenal brush borders during developmental changes.

Duodenal brush border membrane proteins were studied in chicks at different developmental stages. The protein pattern obtained from polyacrylamide gels with 2-day-old chick preparations was distinctly different from that obtained with 20-day embryos. The most remarkable changes were seen in the region of a protein with an Rf of 0.25, an area with high sucrase and maltase maltase activity, and in the region of a protein with an Rf of 0.28, which was characterized by alkaline phosphatase activity. These proteins reacted strongly with carbohydrate stain after hatching.

Alkaline Phosphatase↗