Demographic factors may serve as risk or protective factors for drug use in American Indian communities. The purpose of the present study was to compare drug-use rates among Oklahoma and Non-Oklahoma Indian youth, and test corresponding rates of preventative and protective community, family, and social-demographic factors. Participants' data included 1,928 Indian 7th-12th graders from non-Oklah...

In the present study we have characterized mammalian sphingosine-1-phosphate phosphohydrolase (SPP1), an enzyme that specifically dephosphorylates sphingosine 1-phosphate (S1P) and which differs from previously described lipid phosphate phosphohydrolases. Based on sequence homology to murine SPP1, we cloned the human homolog. Transfection of human embryonic kidney 293 and Chinese hamster ovary ...

The multifunctional nature of classical microsomal glucose-6-phosphatase (D-glucose-6-P phosphohydrolase, EC 3.1.3.9) is now well documented (see, for example, refs. 1-8). Inherent in the reaction mechanism proposed by Arion and Nordlie2 to describe the variety of phosphohydrolase and phosphotransferase reactions catalyzed by the enzyme is the mutual competitive inhibition of various phosphohyd...

The intracellular signalling pathway for alpha-adrenoceptor-mediated negative inotropy was studied pharmacologically in isolated adult mouse ventricle. The negative inotropy was inhibited by GF-109203X, a nonselective protein kinase C inhibitor. Phorbol 12-myristate 13-acetate also produced sustained negative inotropy, which was inhibited by KB-R7943, a Na(+)/Ca(2+) exchanger inhibitor. The alp...

Phosphoserine phosphatase has been partially purified from mouse brain. The preparation catalyzes the phosphohydrolysis of phosphoserine at an optimal pH of about 6.2. This hydrolysis is strongly inhibited by serine. The preparation also catalyzes an exchange reaction whereby the phosphoryl group of phosphoserine is transferred to serine at an optimal pH of about 7.5. Treatment with urea result...

Feeding sheep a concentrate diet compared with grass diets increased the hepatic specific activities of the three glycolytic enzymes studied, and that of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and reduced the specific activity of D-fructose-I, 6-diphosphate I-phosphohydrolase (EC 3.1.3.11). The specific activities of phosphogluconate dehydrogenase (EC 1.1.1.43) and malate dehydrogenase...

We have proposed that glucose-6-phosphatase (EC 3.1.3.9) is a two-component system consisting of (a) a glucose-6-P-specific transporter which mediates the movement of the hexose phosphate from the cytosol to the lumen of the endoplasmic reticulum (or cisternae of the isolated microsomal vesicle), and (b) a nonspecific phosphohydrolase-phosphotransferase localized on the luminal surface of the m...