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D W Moss

Publications and source records attributed to D W Moss.

At least 145 records · Page 8Linked to original sources

Regulation of vitamin D metabolism: factors influencing the rate of formation of 1,25-dihydroxycholecalciferol by kidney homogenates.

The formation of 1,25-dihydroxycholecalciferol from 25-hydroxycholecalciferol by chick kidney homogenates is inhibited by increasing concentrations of Ca(2+). The apparent K(m) for the hydroxylation reaction is 1x10(-7)m, significantly lower than that reported for isolated mitochondria. Separated cytoplasmic and particulate fractions are inactive, but on recombination activity is restored, possibly because of the presence in the soluble fraction of a factor with a high affinity for 25-hydroxycholecalciferol.

Animals↗

Serum -glytamyl transpeptidase activity in liver disease.

Serum gamma-glutamyl transpeptidase (GGT) activity correlates closely with the activities of alkaline phosphatase (ALP) and 5'-nucleotidase (5NT) in various forms of liver disease. Maximum elevations of all three enzyme activities are observed in diseases which particularly affect the biliary tract. Compared with the other two enzymes GGT is generally increased to a greater extent and is thus the most sensitive indicator of biliary-tract disease, while estimations of serum GGT are more reproducible than those of 5NT. However, a group of patients who had been treated with phenytoin and barbiturates were found to have elevated serum GGT activities without any other evidence of liver disease. The apparent effect of certain drugs on serum GGT activity indicates the need for caution in interpreting the results of this test.

Acyltransferases↗

The inducible alkaline phosphatase of rat heart. Some properties of the enzyme and factors influencing its activity.

Subcutaneous injection of isoprenaline into rats produces a rapid rise in alkaline phosphatase activity which is largely confined to the right atrium of the heart. The phosphatase activity of extracts of atrial tissue from treated animals is on average four times that of controls. The rise in activity is largely suppressed by previously treating the animals with cycloheximide or actinomycin D. Comparison of the properties of the alkaline phosphatase in extracts of atria from isoprenaline-treated rats with control preparations shows the stimulated enzyme activity to be similar to that present in the resting state. In a number of respects, including substrate specificity, response to activators and inhibitors, rate of loss of activity on heating and electrophoretic mobility of the native and modified enzyme, the atrial phosphatase resembles alkaline phosphatases from other mammalian non-intestinal and non-placental tissues. These results suggest that the effect of isoprenaline is to increase the rate of synthesis of atrial alkaline phosphatase, and the ability of the tissues of the right atrium to respond in this way may be related to the rich sympathetic innervation of this part of the heart.

Alkaline Phosphatase↗